Various programs (MusicMatch included) have ways of tagging WAV files,
Im sure that is true, but once you tag a wav file in the conventional sense by imbedding the tag information in the file itself then it is no longer a wav file. There is a specific structure to a wav file and imbedding tags corrupts this structure so it is no longer useable by other programs as a wav file. I assume that is what you mean by
they're inconsistent and not well standardized.