Because burning PSX discs requires a low speed 4x writer which is damn near impossible to pull off with modern burners.
I don't know where people keep getting this. I've burned about 300-400 PS1 games over the past 2 years on varying quality of discs at various speeds using a variety of PSX models (including a PSOne) and the only trouble I ever got was when trying to play them on consoles that still had the original optical drives. In those cases they even had trouble with legit discs (as I keep one legit disc for the disc swapping trick on a PS2 slim).
Really, what would one expect from such a drive that's 20+ years old? A brand new replacement with assembly and all only costs about $20-30 and takes no real knowledge or skills to replace (just make sure you order one that doesn't have to be de-soldered).
I'd probably recommend a PS2, fat or slim over an original PSX for most people. I used to play my PS1 games on a PS2 but decided to downgrade a PS1 for the sake of nostalgia and because it just made it that much harder to pick something to play (so many games in both libraries).
Japan gets Arc the Lad Collection and Parasite Eve. We get Rainbow 6 and fucking Destruction Derby.
Yeah, the US selection is a joke. Apart from maybe 5 of those games the list looks about as appealing as the cheap p&p Genesis my friend has with a bunch of games that look like pirates (got Comix Zone though). I just don't understand their choices here. DD over DD2? Persona 1 over Persona 2? WTF?
EDIT: Well, maybe more than 5. The selection looks like half killer/half filler.