[Arran]

It makes as much sense as having VHS and Beta, or blu-ray and HDDVD...

but once the standard is out, changing it would make even les sense. While we might not agree about having the standard to begin with, changing it wouldn't make more sense.

Technically, if the record spins faster, don't you have a better "resolution" to store data, so "better sound quality"? Or am I thinking too digitally here.?

With digital it's the sampling rate and with magnetic tape it's inches per second, but it doesn't seem to hold true with records even though one would think it should. The 33-1/3 singles (not common but do exist) are considered high fidelity but I've never heard anyone classify 45 RPM singles that way. Maybe I'm a bit tone deaf but I can't really disern a difference in sound quality between a 33-1/3 RPM LP and a 45 RPM single all conditions being equal. Nobody would argue that a 78 has higher fidelity then an LP but 78 rpm records are not microgroove either. I've never had a 16-1/2 RPM record so I can't comment on those, they seem to have been most popular for transcription records or for issuing recordings of radio programs, the last 16-1/2 RPM records that I saw were for the U.S Armed Forces radio network. I guess if they were seen as a good enough format for rebroadcasting radio programs the fidelity couldn't have been that bad.
Regards
Arran