Why would you discontinue it if still profits?
Either major retailers would either ask it to be discontinued/stop ordering more or people would have to stop buying them.
If you recall years ago the PSOne was selling for $50 and still selling a few units here and there. I picked one up myself almost.
If the PS2 were to drop to $50 it could sell even more, hell I'd probably buy a backup myself and keep it aside incase my PS2 were to crap out. I know when the Gamecube dropped to $50 I picked up a spare.
It's just that simple.