There are a huge number of contributors that are recognized here on a regular basis. Mark Roberts is only one of many, albeit in my opinion, one of the best. Others include MikeW, Brainster and JamesB, MarkyX, ref, apathoid, CheapShot... a complete reckoning will be quite extensive, but you get the idea.
Why does it bother you that some folks are appreciative of others' work? Provided that work is factual and educational, which it is in Mark's case, I hardly see any comparison to Avery's doings. Totally different situation.
Have you heard of R.Mackey? He's up there too