think about it -
if you're taping, you need to get into the show, you need transport to and from the show, you need a recording device, you need appropriate mics, cables, editing software, hard-disk space etc.
in all aspects, this costs money - given that LP are a big arena act, this ain't cheap - and recording gear isn't either!
if tapers are serious about getting decent audience recordings, they invest a hell of a lot of time and money in it (some people, myself included, do enjoy seeing audience stuff instead of Pro-shot) and for alot of tapers, it's not a hobby but a means of income.
it may not be the same salary-based job as Pooch and the rest of the official FOH/Mixers have, but this financial transience and unpredictability give these pro-audience tapers an even bigger need to market themselves like the NYCBC does, it's a job for them.