Because it's Yet Another Step in the wrong direction, and will be used as justification down the line to get rid of AM/Radio/Analog Radio a bit more or entirely. Keeping it around, or in a car, may be the wrong or inefficient way of solving the problem of comms in an emergency. But it does mean that we "force" the lingering of the tech in some way, so as to not let it be dismantled in the relentless march of whatever is causing these kinds of things to disappear.

It's a quirk or random fact of history that they got put into cars but not houses, but that doesn't mean we should get rid of it. It's smart and reasoning people like you and me that look at this and think "ugh, no need to have it in a car, we can have it in a bug out bag and it'll make cars cheaper, etc". But that kind of thinking is wrong for society past a certain point.

Before we know it, we'll own nothing, we'll rely on Daddy Government for everything, and we'll be happy! Maybe they'll let us own a Digital Government-Issued Codec-Infused Satellite Radio®, so they can reach us at all times.