I don't know what games you folks were playing, but the ability to start a game with your old character, complete with previously learned skills/spells, was EXTREMELY rare. It's done in expansions only, if memory serves. ME2 is no expansion, it's a stand-alone game.
If you actually were able to import your complete character, it would be just about impossible for new players to play. They aren't going to understand what skills do what and, when they get done with their uninformed building, they are going to take several hours to figure out what they are doing. You can't balance a game for both kinds of players.
You're too young, perhaps
Pool of Radiance
Curse of the Azure Bonds
Secrect of the Silver Blades
Pools of Darkness
Champions of Krynn
Death Knights of Krynn
Dark Queen of Krynn
Baldur's Gate
Baldur's Gate 2
Plenty of others as well.
Still, plenty of CRPGs choose to "start over" - but the vast majority of them aren't PLANNED as trilogies. That's the primary difference here. Bioware had the PERFECT opportunity to plan for this to happen, because they knew from the start that they'd have 3 games with the EXACT same character.
That's what I called a missed opportunity.
In any case, it was never a problem before - having players start with a high level character. Anyone claiming that the Mass Effect system would be a challenge for new players to figure out, even with a high level character, must think VERY VERY little of new players.
It would take all of 5 minutes to absolutely exhaust all options during combat
In any case, what you do is make a small tutorial introducing powers - and having new players either select a pre-made character with solid choices, or let them assign points during the tutorial as they learn the powers.
Bioware opted for the easy way out, because they didn't want to spend a week thinking about good ways to handle this. They'd rather claim it's impossible and not come up with creative solutions. That's because they have no creative vision whatsoever. Anyone willing to see with their eyes open, need only look at the first game - and see what they did with the inventory system - and how they changed that.
In fact, they obviously couldn't handle improvements to the system - so they pretty much abandoned every RPG mechanic, and turned it into a streamlined rail shooter movie. Talk about safe choices, yawn.
Look at Dragon Age 2 for further evidence of complete creative absence. They're throwing everything they spent 5-6 years creating for the first game, out of the window for a quick buck.