^O'Brien was an Enterprise transplant too, & there is some truth to the senior staff having old friends mentioned or creeping in on occasion, but with that said, it's kind of hard to disagree with any of the sentiments posted so far
O'Brien's a little different because he wasn't a senior officer. His DS9 gig was a huge promotion for him, as he was only a transporter operator on TNG. In any case, I stand by my earlier comments. The Enterprise
was the most sought after assignment in Starfleet, so it's not surprising that some of the senior officers and department heads would be somewhat snooty, but for all of them to be that way doesn't make much sense. Picard was never that way. The problem seemed to start with Riker and work its way down.