Why Are Mono LP's So Undervalued By Most Classical Collector/Listeners?

I think its great that mono issues aren't as popular.

Leaves me with the opportunity to grab spectacular Classical and Jazz from the late 50's early 60's for cheap.

I particularly like vocal mono recordings from the divas. The 1958 Julie London album "Julie is her  Name" doesn't get any better.

 Listen to "Laura" -breathtaking on a decent setup. Easy to imagine Julie London...VA VA VOOM.

Yes, imaging is more apparent with stereo. With mono, its more subtle. I tend to concentrate on featured artists and their instruments like a Gould sonata or a Heifetz concerto. Some of my Glenn Gould Columbia mono’s are just "in the room" for me. With these type of recordings. it's more of a "what" than a "where" experience for me. 

The Julie London monos are spectacular at capturing the sense of warmth and intimacy of her lyrics. BTW, I think she slays Diana Krall.

Tablehockey.
I actually have that exact Julie London album in mono.... It does not get much better for female vocal.

Was just digging out mono recordings the other day to try with a new phone stage that also has a mono switch, can't wait to try them and the phone stage with another arm wand with my Dynavector DRT XV1s that I use for my mono recordings even though it is a stereo version, have used it that way every since I read an article by the DRTs creator challenging owners to try it that way and have to say that it is really good, so good I never sought out a mono cartridge for the task, also only have maybe 100 mono albums. Looking forward to listening to them this weekend. Enjoy the music