The unintended consequences of this will be millions upon millions of compromised devices all over the world with owners completely unable to solve the problem themselves.
Or the router manufacturers will properly modularize their designs so that the parts you need to replace to fix a compromise are separate from the parts that ensure that the radio stays on legal frequencies, under legal power limits, and uses legal modulation modes.
The cheapest way to ensure those things is to do it in software, which is how we get into this situation in the first place. Modularization will cost more, and what manufacturer is going to willingly sign up for that?
Companies would do lots of things if they could get away with it, as someone commented on here a while back (and I wish I could find it) "It's a corporation of course you can expect it to shit on the kitchen floor"