What are the negative consequences of not bedding in disc brakes? It's common knowledge that disc brakes need to be bedded in. But I've never heard or found a description of what happens if you don't bed them in.

Given the number of BSO's that now have disc brakes, and the likelihood that 99% of those never get bedded in, I'm guessing that the consequences can't be too incredibly dire.

But what are those consequences? Reduced braking power? Uneven braking power? Squealing brakes? Reduced lifespan of pads and/or rotors? Are those consequences long term? Or do the brakes "naturally" bed in with regular use and the consequences are only short term?
I think your last comment is the operative point - it will happen anyway sooner or later.

The technology here is basically the same as with automobiles. You start off with new pads and a clean rotor. The bedding in process involves the deposit a small layer of pad onto the rotor (mixed in with a little frictional heat).

Until you have that layer on the rotor, braking could be less powerful and uneven.

You don't ask this, but for completeness, the rotor should be cleaned whenever the pads are changed, using isopropyl alcohol. And, once the rotor is clean, the bedding-in process will start over.

You don't see an awful lot on this subject if you look on the web at bike pages, but as I say if you start looking in the context of cars, there's lots out there and it is definitely not new technology.