I rationalize cutting up "good" jeans with this thought: I bought these jeans at a non-profit thrift store for $.25 per pair .... meaning they had been on their racks for at least 3 months or more and nobody bought them. If I didn't snag them up, they would end up in bags going to workshops (or sent overseas) to be cut up into rags. Better useful rag quilts than rags! I even use pockets on denim pillows or wall hangings, zippers get made into flowers or other decorative trim and even those seams sometimes find their way onto wall hangings or some other useful accessory.
My justification ..... hope it helps!