For a small minority of the hardcore gaming community yes, this may be true, but outside of this forum the overwhelming majority of people that buy this game won't even know what aliasing is, or even notice the frame rate drops, I have friends that are classed as the 'average gamer', don't post on forums etc and buys games based on cover art and synopsis, and familiarity, even trying to explain slow frame rate to them is a chore, they play games like GTAIV on the PS3 and to them everything is fine. The main complaints I hear from 'regular' gamers are about glitches, like clipping for example, this is understandable and I think that does break the illusion of the in-game environment, these are the only complaints I ever seem to hear though, I never hear "man this game has lots of jaggies" or "the frame rate is really slow on this game", never, not unless it's from a fellow gaming nerd.
So my point is that the development team is on a limited budget and schedule, why are you going to spend hundreds of thousands of dollars on extra development time on tweaking the engine to please that 0.05% of hardcore gamers?, I really don't see the point, yes in an ideal world it would be nice if all games ran at 60fps with 4xaa @ 1080p or whatever, but for a game like this it's just not worth it, you'd just throwing be money down the drain.