After slogging through World of Warcraft for several years, the last thing I want in a game is something that requires me to basically live a double life. I'd like an MMO where I could pop in and out, instead of dedicating multi-hour blocks that become the equivalent of a part-time job by the end of the week. And that doesn't include researching content for efficient strategies, researching in-game equipment for optimized tactics, bickering with people on the Internet about various aspects of gameplay, or ultimately regretting all the time I didn't spend socializing, reading books, accumulating income, learning a real-world employment skill, exercising, eating decently, or traveling.
I think that's the whole point of this 'horizontal leveling' they're talking about - you'll be able to boot the game up after two years of it being out, with a new character, and still be of some use to your faction. You'll be able to pop in, do a quest, and then leave again. Of course, it would be bad form to start a quest with some buddies and then AFK just as it starts to get hard, but that's the whole point of an MMO - your actions affect real people.
You could well just be complaining about MMOs in general though, in which case I would suggest to you a path that didn't involve spending several years slogging through WoW. I used similar advice to great effect after realising that I don't like vinegar on chips - the problem wasn't the vinegar, it was that I kept eating the damn stuff. Although I didn't care enough to bicker about it with random people, or spend lots of time reading up on the best vinegar, or choose vinegar over stuff that I like more; I also didn't then go on food sites and bring up my dislike of vinegar whenever someone mentions it. Maybe the problem is that you got super-anal about something you didn't, in hindsight, give a monkey's uncle about?