You can be upset all you want, but unless it was adverticed as "easily expandable" or whatever then your upset-itness doesn't matter.

I don't know what you are going on about carpets, but to relate it to topic: You are well within your rights to choose the actual lamp in which you use the bulbs.

I don't get why people use such bad examples/metaphores in this topic. Car just is nothing like a light bulb. Another shitty, but little better example would be a gaming consoles. You can't just make a game for new consoles and sell it in stores without going through Microsoft or Sony. Are they within their rights to restrict who can make what kind of games for their consoles? Are they entitled to profit off of each game sold? After all they "just" made the consoles, we buy them, shouldn't we get to choose which games we play and how we obtain them?