I know its all been gone through before, but here's my two cents.
1) I'm from Sydney where there are tons of caches and I don't think I'll see them all in my lifetime
2) I'd like to be able easily see which caches were highly regarded by other cachers.
3) Rating caches is a good idea.
4) I wouldn't want to put off first-timers with a bad rating would be my only concern, but I personally would be tempted to give a first-timer a couple more stars for effort anyway.
An award system would be nicer maybe, but also prone to croneyism, more complex, and less workable. Why not just a "Rate It When You Log It" system - so simple, so obvious, so useful, so why not?
I know, I know, many people have reasons why not. Personally I think the benefits outweigh the risks.
Blocko (& his 2c)