> Laserdisc players were unreliable at the best of times. Run it for extended periods > in a poorly-ventilated cabinet with constant seeking and it'll be even less reliable.
Add in various forces on the cabinet from playing and the occasional kicking of the cabinet when someone loses and it gets even worse. Same reason games that actually ran off a CD/DVD are rare outside of the 573/Bemani stuff. (Sega's GD-ROM system copies the entire disc to a RAM disk and runs it from there; the optical drive is never active during actual gameplay).