My 360 did scratch up discs for no reason. We had it horizontal and never touched it except to load discs. We had 2 games ruined that way. We called Microsoft and sent the unit to them. They replaced it and it’s been working fine ever since.
I recall reading somewhere that in space-conscious Japan, vertical designs are favored over horizontal ones as they take less shelf space.
My PS2 is very old, one of the first production runs. It hasn’t scratched any discs, but it has more trouble reading them when it’s vertical. My guess is that parts of the drive, particularly the spindle, tend to get out of alignment more easily when vertical. It may be a function of the console’s age as well.