Their site, their rules. They could decide to remove Bitcoin trading and ban anyone who mentions the word Bitcoin, or the color orange, or that owns a goldfish. If you don't like it, don't use them.
*edit* because this comes up so much, and people keep spreading misinformation, not that this will help, Balthazar, a very long time chat mod and a close friend of BTC-E created NVC, its not really a shock that BTC-E started trading Novacoin, it was more than likely a favor to Balthazar, he did give them a bunch of coins as a present, but then when people started getting pissy, they sent all of the coins to an unusable address. I don't know about the FTC situation.
The original doge early adopters intention was to pump doge, and then dump it on stupid people who would buy in on a dead meme (I was there during the conversation but decided I wouldn't bother with it) the question is, have they already done so, and did doge recover, or has it yet to happen. It was all done publicly, so I'd be surprised if BTC-E wasn't aware of it. They probably A. aren't interested in listing it in the first place, or B. would like to wait and see how everything turns out.
Ohh my always nice to see the truth come out