Why would you want backwards compatibility? To play games you already own and like instead of buying new ones? Now now, don't be ridiculous.

Sarcasm aside, I do wonder how technically challenging it is to keep your system backwards-compatible. I understand console games are written for specific hardware specs, but I'd assume newer hardware still understands the old instructions. It could be an OS question, but again, I'd assume they would develop the newer version on top of their old, so I don't know why it wouldn't support the old features anymore.

I don't want to cynically claim that it's only done for profit reasons, and I'm certainly out of my depth on the topic of developing an entire console system, so I want to assume there's something I just don't know about, but I'm curious what that might be.