I haven't ever played anyone except my brother with my marines, mainly because we always proxy due to the fact that none of us has got a proper army (well, he has his Eldar that he really doesn't play that much).
I have, however, sensed something about the gaming community. People are really tired of the "poster boys", and the armies that are better than all the rest. I have been out of the loop for quite a while, but I know that Daemons used to be really good in WHFB. I know this isn't strictly related, but stay with me. In Fantasy I have a Goblin army of around 1000 points, with an orc warboss in it. It's supposed to become an orc & goblin army some day, but I only have Gobbos this far. Anyway, every time I've brought it to play (never really won with it
), I get bucket-loads of respect for bringing them. Why?
People love underdogs. Everyone knows that Gobbos aren't all that good (at least they weren't in the last edition), and therefore people rooted for me. Even my opponent, kind of. I played a double, where I allied my goblins with some ogres and we faced down dwarves. My goblins got completely smashed and even my dreaded fanatics didn't do much - except for bringing down half a unit of Longbeards (I think they're called). Even the dwarf player cheered on that.
My point is that people don't like poster boys and they don't like the race that is currently "best". People rightly fear Marines, they are a good race to play. Add in their status of poster boys and a great lot of people will have animosites against them. People are generally sore losers and they won't forget being beat by the "newbie army".