Am I totally nuts or just a bit off?

Schubert, glad that you are enjoying the change. I love Dakota Staton as well.

The early stereo effects - vocalist in one channel, band in the other - drive me crazy. I have been enjoying some mono Nancy Wilson and Jo Stafford of late.

If the music is cool mono can sound fine to a point...stereo sounds better though because that is how the world sounds if both of your ears are working, assuming the music was well mixed and recorded. Live music spacial cues are mostly gone from mono. When I mix live (mostly jazz these days) shows you really have to do mono mixes to each side or people sitting nearest a speaker won't get everything, so I add in a small amount of stereo reverb to make it sound more lively and it goes a long way toward tricking the audience into thinking they're having fun.

Tonywinsc, you B&W analogy is dead brilliant !

Wolf, what does sitting nearest a speaker mean?
I have two and I sit equidistant between them and my ears look equidistant in the mirror.

From a technical standpoint stereo has nothing to do with the number of channels as long as it's more than one. Two, four or twelve channels, they are all stereo.
Most audiophiles should see the value in capturing a live performance with each instrument/section in it's own channel. The way we would hear it in a natural event. We hear in a 360 degree environment with emphasis on certain forward perspectives, but we still hear from left to right and even behind.
Yes mono can be good or even great, all things being equal stereo has at least twice the sound potential, Realistically it is an exponentially better recording platform.

Wolf_Garcia otherwise explained it perfectly from a practical standpoint.

Yes, stereo has all the advantages on paper. But its how its used recording by recording in each case that matters. Other than with the rare (these days) simple two or three microphone recording techniques what goes into the stereo mix is a product of what the production crew decides to mix in. It may or may not resemble anything like you might hear live.

Mono on the other hand takes that variable out of the equation. In certain setups in certain rooms with the right acoustics, it can sound very much like what a live performance in the same space would sound like with all the stereo mixing and mastering out of the picture. At least that has been my experience.