[palata]

Yeah it's a good question, and in the end it's arbitrary. I would say:

1. Because e-waste.

2. Because if I buy shoes, I own the shoes. If I buy an electronic device, I own the electronic device. It should not be legal to add a mechanism in my shoes that allows the manufacturer to make them stop working as shoes whenever they want.

Hardware manufacturers don't open source their firmwares because they see it as a competitive advantage (why not, sometimes). But they should allow someone else to write their own firmware. That is, they should provide minimum support for that. Right now it's not that they don't provide minimum support: they actively work on making it technically impossible to do. And the law, through the DMCA and the likes, makes it illegal to reverse engineer.