Quartz isn't a lazy bum. He just sucks at any and all jobs he has ever done, no matter how simple. And it's not like he's dumb either. He just gets distracted very easily. But he does like food. He smiles.
Thanks.
In fact, he isn't even a bum. He lives very nicely even if he doesn't live in a house. Being an animorphis has made him born with a more animalistic mind so that is just how he lives.