What's so bad? He only has two onscreen personae - variants on the Fresh Prince, or a Tom Hanks-esque earnest Oscar performance. Sci-Fi roles - I, Robot excepted - fall into the latter.

Personally, I find the Fresh Prince character arrogant and irritating, especially when he shares the screen with Carlton. Also, he's confessed in interviews (sadly not online) that he had no acting experience when he was signed to the role, so basically played himself - thus I feel justified in taking a dislike to him personally due to my dislike of the character (and there is some corroborating evidence that he's an arrogant asshole in real life[1]).
Finally, a lot of the raps he recorded for his various film roles are unacknowledged rip-offs (witness [2]).

1: http://www.bvbuzz.com/2009/06/17/sitcom-saga-tv-mom-claims-will-smith-was-no-prince/4
2: http://www.youtube.com/watch?v=td25kTqvl1w

I can think of several good reasons to give kids Linux laptops:

1. Much much less expensive - you'd only need a very low-powered laptop for it to be useable, and software is practically free.
2. Likely to be much more useful to them in the future - knowing Linux makes you far more employable now, so what's it going to be like in 10 years?
3. If you don't give them root access, they can't fsck them up.
4. Far less games - I know, I know - I'm not against kids playing games, just trying to see it from their teachers' perspective.
5. Less potential for 'computer crashed & ate my homework' excuses ;-)

Of course, you'd have big problems teaching kids how to use it; but, hell, if you'd given me a computer that just ran vi when I was a kid, you can bet your sweet ass I'd have used it ;-)