It's all about head space. Caring about money is quite a binary thing: once you engage with it, it's a huge commitment - intellectually and emotionally. People who don't care about money understand that they're only inches away from caring - and that the moment they cross that line their whole attitude is going to have to change. That's why they're wilfully disengaged from these issues. They don't want to set that process in motion. Money has a gravity all its own - it sucks you in.
People who do care about money don't have a problem. Money proves its own importance in a very material way. So the commitment always seems justified.