I've been playing MMORPGs since the beginning (or had, I've pretty much stopped since modern MMORPGs suck).
Sub-based is the way MMORPGs should be.
F2P is trash. It's a system designed to maximize profits and it's marketed to stupid people to make them think it's doing something for them when it's not. F2P games are lower in quality and more importantly, the experience of playing a F2P MMO is of far lower quality.
Good sub-based games are successful. Bad games are not. Derp. F2P is just a way to extract MORE money from players than they can get via subs, and in today's corporate world where everything has to be monetized and must involve maximum profit extraction, what we get are super crappy MMORPGs, often F2P, purely designed to make money, and gameplay be damned.
As a side note, I think FFXIV the author mentions is a terrible MMORPG. It has too much console influence and ties (weak simplistic graphics, an ungodly amount of loading screens, simplistic character/skill system, weak gear system with 1 weapon per class and no choice, 20+ levels of tutorial out of 50 as if everybody who plays is a complete idiot, the fate grinding BS is just xp welfare for people who are too lazy to even do solo idiot mode questing, and so on. It's pretty even though the graphics are simplistic. SOME of the group content is good. Personally, I didn't last the free month since I capped and was doing endgame so fast and found the endgame to be pretty lame and had enough quickly.
I miss the days when MMORPGs were all about grouping - always - and about challenge and danger. The new style of MMORPG that tries to be everything to everybody, goes for wider appeal, and is mostly solo with tiny bits of optional grouping is garbage. I own a ton of games, most of which have excellent single player. I don't play MMORPGs to solo next to idiots named "xXLegolasXx", I play MMORPGs because they offer the unique opportunity to do complex content WITH other people.
To me there are several benefits of the sub-based model.
For one, all players have the same potential. How well you do in the game depends on how well you play and how much you play. Not how much cash you're willing to throw at the system. You all pay a static fee, you all have access to the same everything, you all have the potential and same ceiling. With F2P, you are often gated by cash barriers or there's little hope of ever playing the full game without throwing down cash, and quite possibly more cash per month than you'd ever pay in a sub-based game.
Secondly, the players tend to be of higher quality and take the game more seriously. MMORPGs when done well require a significant time investment. This isn't a bad thing, it just IS. The attempts to make this hardcore genre less hardcore, more mainstream, more wider appeal, more casual, have just resulted in a lot of really crappy games. Players who are committed and playing a sub tend to take things more seriously because they're firmly financially invested. With the more casual F2P games, players are expected to come and go, to not take things seriously, to have less permancy, and so on.
The casual come and go thing works great for soloists who probably shouldn't be playing MMORPGs anyways but it's bad for the more serious players who want to take on the beefier content that requires groups. It's hard to keep a guild together, or do raiding, or even do regular small group adventuring when the people in your circle of friends only show up randomly every other day/week/month. With subs, people tend to play more consistently. With F2P, you may never see them again.
Hell, it's hard to meet or get to know people to even attempt to forge the relationships to build guilds or regular groups when you may never see the same person twice or see them over time. Between F2P and solo emphasis the social element that used to be core to MMORPGs barely exists any more. Now it's a bunch of preteens or adults acting like children yapping incessantly about stupid crap in public chat - that's the new social, or socially retarded, in MMORPGs.
Third, F2P with MMORPGs is pretty much going to involve pay to win, which is pretty much cheating. A core concept of any RPG is gaining stuff and growing. You gain loot and better gear. You can achievements. You gain xp and level your character. You acquire STUFF. If you can buy that stuff in a cash shop or grease the wheels with perks thru the cash shop you undermine the very core of RPGs.
Anything you can obtain for your character SHOULD come from playing the game, be it a new weapon, piece of armor, a vanity clothing item, a mount, etc. If you can buy it for cash in the cash shop, you undermine the whole reason for playing. If you can buy boosters to increase the rate at which you get xp, loot, magic items, etc, you are undermining the core of the game too.
For MMORPGs, even selling service type of stuff like bank slots, bag slots, character slots, etc, is iffy too, since a lot of that can be tied to earning your way thru the game as well.
Take all of that away and what then could they sell in cash shops to pay for the games and profit? Not much, really. So they sell pay to win.
Worse, increasingly more, games are now selling cash for gold, which previously WAS bannable cheating in sensible MMORPGs. It was the "chinese gold farmer" real money trading thing that people would get banned for. Some F2P games have been selling gold for cash and now even premium games WITH SUBS are selling gold, like WildStar. Oh, they market it well, and they wrap it in BS, but ultimately, players are paying cash for gold, which is the ultimate in pay to win as far as depth and flexibility. Want that costly new mount? Cash > gold > mount. Too lazy to harvest your own mats for crafting? Cash > mats > done. And so on.
In the mixed games where you can earn stuff or buy stuff for cash, why should anybody play to earn? Part of the enjoyment of earning your stuff in RPGs is the sense of accomplishment from doing it. But that is kind of robbed when the guy next to you has all the same stuff you have, except he paid cash for it. Kinda pulls the rug out.
With subs, you have to earn your way. Sure, there's bad design and bad management that allow for 3rd party gold to play a big part (poor design that makes gold a large part of success leads to people cheating buying it). Poor design often allows higher level characters to babysit and play the game for lower level characters (powerleveling and such), but those kinds of issues COULD be minimized to keep the playing field level and the games more pure, if designers wanted to.
Part of the problem is, though, who knows what designers really want to do? MMORPGs cost a ton to build, so they fall under the umbrella of corporate gaming, and corporations only care about one thing. Money. How do we maximize profits. How do we pay and give people less to produce crap we can overcharge other people for more? So maybe there are MMORPG designers who'd like to create quality games that provide the best possible MMORPG experience, but we'll never know it, because the corporate bean counters are pushing design now, and they're only interested in creating cheap, TV-like mind candy for the masses that pulls in the most profit.