You make some points, but:

a.m. radio is even worse for fidelity, but many ( most )
listeners are tuning into that for music. so in your
estimation then, a.m. radio is an abomination is it ?

Just out of curiosity, what part of the world are you in? There's virtually
no music on AM in the USA. Is there still a good bit in Britain?

Actually, rather high-fidelity AM is possible, though rare. At the
transmitter end, you need to demodulate the transmitted signal and include
it in the audio feedback loop, so you're controlling what actually goes out
on the air rather than just what goes to the modulator. At the receiver
end, you need wide bandwidth, much wider than we normally have. An AM radio
can be aligned for high fidelity by first doing a conventional alignment,
and then tuning alternate IF transformers somewhat high and low. The signal
gets weaker but has a lot more treble.

Fifty years ago, hi-fi AM enthusiasts used TRF rather than superheterodyne
tuners (and could only get strong local signals, but they sounded very
good). If there were music on the local AM stations, I'd experiment with
that myself.

One big reason hi-fi AM hasn't caught on is that AM is noise-prone. FM can
exclude noise; AM can't.

BTW, what ever became of AM stereo?