As a purchaser of hardware, I want full control over the stuff I own, including the right to modify firmware. But I'm also sympathetic to hardware manufacturers

As a purchaser of hardware, I want full control over the stuff I own, including the right to modify firmware. But I'm also sympathetic to hardware manufacturers, especially in this day and age where information travels so fast. A hardware company can say your warranty is void if you modify your purchase's firmware. But it can't stop you from flashing back the original firmware, saying it was broken when you received it, and still making a bogus warranty claim. Nor can it stop you from writing a terrible Amazon review about how complicated the product is, when all your complaints are self-inflicted from modified firmware you found online that the company didn't even write. Companies are responsible for the entire relationship between their products and their customers. So I can see why they want to define hard boundaries around it.