Lot's of responses since I started typing this and got distracted.
Here’s a list of reasons off the top of my head:
-Limited playback opportunities.
-Increased complication in understanding the various approaches in recording for surround (2-channel stereo is already complex).
-Increased recording hardware complexity and costs.
-Increased editing complexity, complications, and lack of robust support in commonly used editing software.
-Increased storage requirements.
-Lack of standardized universal, free distribution/playback formats.
-Doesn't fit easily into the model of recording to promote lesser-known acts which drives much of this taping culture.
-Doesn't fit well with the modern lifestyle listening habits of most listeners.
-Misunderstandings of the advantages over 2-channel stereo, and mischaracterizations of expected disadvantages.
And the biggest one--Most simply haven't been convinced. They haven't heard good enough examples to be convinced these hassles are worth making the extra effort to overcome them.
Some of those challenges have become less problematic than they used to be, given the on-going advances in computing and recording hardware such as inexpensive multi-channel recorders and other gear such as your TetraMic. But all of them remain challenges over 2-channel stereo recording and playback, some of them quite significant.
Here’s a realistic if somewhat dark view of the current state of things. I’ll follow up later with the brighter evangelistic take, because really I’m a true believer and optimist-
The field of amateur live music recording is relatively small, within which surround recording will always be at best a sub-set. I've found very little interest here at TS in even discussing surround and potential ways to go about recording it. I’m unaware of anyone else actually making live music recordings in surround. Here's the previous attempt at a general discussion-
http://taperssection.com/index.php?topic=7947.msg1658425#msg1658425. That was the original
Surround live recording thread from 2003. Todd E bumped it in 2009 and that's when I became aware of it, I bumped it again in 2011 and it immediately died a quick, sharp death. Since then I've given up discussing it around here, but still sneak mention into discussions when it's somewhat relevant. That rarely goes anywhere other than a PM or two on rare occasions.
There have been a few users of various portable Soundfield microphones on-board here, although all of them have used the microphones to produce 2-channel stereo rather than surround, as far as I’m aware. There are some some DTS encoded surround recordings from the early to mid 2000’s posted on Archive, Etree and elsewhere, but all of the ones I’ve sampled are either simply dry SBD routed to the front speakers with a stereo AUD routed to the surrounds, or are otherwise made from a few conglomerated 2-channel stereo recording setups with the surround being at best an afterthought and not well implemented.
Almost no one has a system setup for proper playback. Most home theater cinema systems are sub-par at best for good surround music playback and not up to the quality of their stereo playback, their car stereo, or their headphone system. Most commercial surround sound music releases are a joke and not worth the effort to reproduce them. On top of that, very few listeners are even willing to take the time to sit down and experience something like a fully immersive surround listening experience which commands all of one's attention. Readers here are a few of the last remaining exceptions to that, but how many outside of us even have decent stereo systems much less take the time to sit down an listen to an entire album or live recording?
[edit to add link to previous TS discussion above]