Fair enough. But Preston Gralla is certainly not like a walking MS PR firm. Compare and constrast Preston's stories with someone like John Gruber for Apple. Gruber has written maybe 100 blurbs about Apple in the past year and maybe one that was critical. Daniel Dilger is basically the same -- except maybe he hasn't yet written the critical Apple article yet.
Preston OTOH regularly writes critical MS articles, more often than he writes those that defend MS.
The author who refered to Preston as the equivalent of an MS PR firm doesn't know his history well.