I completely drewed a 90's Specialized Hard Rock someone gave me, d-hanger gone, canti brake studs gone, cable guides gone. It's a light frame as it was, super light now. I converted it to a coaster brake single speed and ride it every day. I would never have ridden it as a MTB, and it was bound for the dump if I hadn't got my way with it.
A bike is a tool, it can be sharpened any number of ways.