The problem is that the PSP disc casing is always opened. Since it's a portable system, no matter what you do, it will always let dust in and not out. Anyway, Sony got it all wrong from the start.
I agree. No matter how well you take care of your stuff, your always going to run the risk of dust, scratches, or something else unforeseen to happen. Why they didn't go with the more nicer MD caddy case is beyond me. Sure, you save more money, but in the long run it just causes more BS for people. Which is why people started loading games on Memory stick instead, which is why.... PSP GO!
The GO was a half-assed attempt to sell the PSP to the kind of people that buy an ipod Touch, even though a lot of those doing it are mostly tools buying into the brand, and would not be caught dead using a console in public. First of all, why a slider? flip is way better and protects the screen. Second, why use NAND memory? why not fit a big 60GB 1.8" drive coupled with a 512MB buffer? it would be both cheaper to make and have more than enough space for games.