I don't want to argue, but I don't think those assumptions are correct and even if some are extrapolating them on manufacturers of consumer devices is still wrong. And this is important, because not understanding their view of the world is not going to give us any ideas of how to improve security.
I get not wanting to argue. How about instead you give me links explaining "their view of the world" with its principles, challenges, and/or tradeoffs. Even if I disagree, I might learn something about another sector of the market that I can tailor recommendations or solutions to.
