I agree with OP that Head-Fi has had an M50 problem. I agree with the some of the aggrieved defenders, too, that one can have worse problems. Maybe the best thing about this thread is that it induced several members to overcome their shyness and post for the first time.
Were I new to headphones, I might have bought M50 based on some of the reviews linked to. But in response to those who mentioned Tyll Hertsen's high opinion of them, they should read him more carefully or quote him more honestly. "Pros and avid enthusiasts would do well to spend the extra to go for the SRH 840 . . ." I agree with him, though I wish SRH840 had ATH-M50's build and comfort.
Besides everyone's sensible explanations for the popularity of M50, I've thought of two other factors:
OP mentions many newer members buying it, liking it, and recommending it without sufficient comparison. I suspect that a good number of the members who moved on bought mostly more expensive products, so they still don't know what else to recommend when someone asks them for something cheaper. (I listen to cheaper headphones when I can partly in order to know what to tell acquaintances who don't want to spend $500 on a system. But I'm still somewhat at a loss because many people I've met think even $100 is a lot for headphones.)
The name "M50" definitely helped. "M" is one of the more popular letter designations in tech (after X, S, and Z). "50" is easy to remember and sounds solidly mid-range and approachable. Even the company name "Audio-Technica" might have helped. It makes its purpose obvious while sounding pleasantly sophisticated.
Edited by Claritas - 11/17/13 at 12:23am