That's probably because you compare it to other modern RPG's which has even worse gameplay.
Character development - Not that many options, completely unbalanced.
Crafting - Broken and almost useless.
Combat - Fun and good in beginning, lackluster and broken towards the end, quen, quen, quen, roll roll roll or just click click click.
Hard Difficulty - Extremly easy.
Quen sign - Completely overpowered.
Timed click events - Does anyone likes those?
Arm wrestling - Ok for a mini-game but also really easy.
Dice Poker - Only luck.
Boxing - Really easy and more or less same thing as timed click events.
Third Chapter - Broken and almost no meaningful combat. ( Haven't tried enhanced edition yet this might change my opinion regarding that )
Monsters - There is only really few different kind of monsters and you quickly learn how to fight them. ( Because the cost per monster is so high when the graphics is so great )
Human vs Human combat - Better, but still flawed, and there is too little of this.
There are a lot more issues this is just a scrap on the surface.
You can dissect any RPG, including the good ones, and make an endless list of faults.
In any case, regarding TW2:
Arm wrestling/Dice Poker/Boxing: Those are optional minigames that are there to add some flavour. They are indeed too easy though and perhaps some bigger challenges might be beneficial. But a game doesn't suck because of optional minigames.
QTE: I agree that they are unnecessary and do not add anything to the gameplay. But outside of the optional boxing minigames, there are only a few instances where QTE's are employed so they cannot be considered part of the core gameplay.
Quen spamming: This is one of the biggest general complaints. In my first playthrough I didn't rely on Quen since I chose a different build and experimented with different tactics. So a simple solution would be to not use Quen at all
.
Also, as a response to this criticism, they have reduced the Quen effectiveness in the EE version.
Hard difficulty setting: I found this setting to be easy too. But don't forget that many other players complained about the difficulty and were very vocal about it. Perhaps you are just too experienced and too good as a gamer
.
I played the EE version at the Dark difficulty setting and that was considerably better than hard. (I'll admit that I don't have what it takes to go for Insane difficulty
)
Rolling/blocking:: For me personally, what bugs me the most is the mandatory reliance on rolling and the fact that you cannot walk while blocking.
IMO, a simple solution would be to make blocking a toggle with the E key where you could walk during the blocking stance. In that case you would have the option to walk away instead of having to roll away. Also, the stamina mechanics should be revised IMO to include rolling as well to avoid roll spamming.
I think that there is indeed room for improvement in combat but something that "sucks" would be beyond solution or simply broken/unfinished.
Crafting: What is wrong with crafting? I crafted some good armours so I don't see how it is useless. In any case, as opposed to some players, I don't care at all about crafting mechanics so I might be immune to crafting flaws.