The reason he had 8 PS2s was either he was modifying them for people or like many PS2 owners has had a number of them go tits up. Usually the optical drive is what fails, but it's worth keeping the dead ones for spares bits and bobs (there are 13 or more ps2 versions so sometimes there is litte to no internal compatability).

I myself am on #4. It never goes anywhere or is misused. They just stop reading some kinds of media after a while. My current one read everything I put in but sometimes takes longer then a new one to read a disk or get the occasional read error.