They could also decide to allow their devices to be unlocked in a secure way, instead of us having to rely on vulnerabilities, and then them having to fix them.
Devil's advocate: perhaps Google is taking a loss on the $35 device in exchange for user lock-in? I doubt the immense R&D behind building it would have been worth it otherwise.
I'm not arguing against unlimited freedom - just arguing against the expectation of unlimited freedom when all things are considered.