The only Markbass fanboy I've encountered was a salesman at Guitar Denter in San Antonio. Really obnoxious bastard who just couldn't believe I wanted to try a bass through their G-K display instead of Markbass and tried to argue with me when I told him the G-K sounded better to me. Then after I started playing, the jerkwad pulls a bass off the wall, plugs into a Markbass and starts slapping the shit out of it trying to drown me out. I put down the bass and walked out.
That store was very near a friend's house so I went in again a couple of weeks later to try the same bass through the G-K display. No salesman in the bass room. A minute later the same guy walks in and does the same thing. Walked out again, only this time I phoned the general manager after I got home. Never set foot in that store again.
That sucks, and those "tactics" are prevalent throughout their company. I'd imagine that their margins are pretty high on all the stuff the salesmen regularly try to force-feed us (Markbass, Ocean, etc.). I had similar experiences here in the Raleigh store and vowed to never go in there again.
I've also called the store manager once (which is something I don't do often) to bitch about their salesmen/guitar-heroes and the lack of customer skills they possess - due to a similar issue in the bass room. The fact that I have to go to a sales counter, wait on a line to get a cable to plug in a bass is ludicrous. Then, that guy hovers over you telling you everything he knows about every instrument or amp you touch - and then stands there awaiting your decision. These guys need to understand that to some folks, a $300 purchase is a huge deal, while other have the means to drop a couple grand without batting an eyelash.
Just recently, I went to the Raleigh GC (looking to try out a few amps) and there must have been 3 or 4 cables lying in the bass room. One guy came over to me, introduced himself and told me to find him if I need any assistance. Perfect. I like the fact that they seem to be trying to improve...
With a couple of kids into everything musically (guitars, vocals, bass, drums, recording/production, live shows, etc.) the big box stores are a necessary evil for me.