Will people vote with their wallets? I highly doubt it. MCM love bombed Dublin when it arrived, and hordes went to Dublin' first big comic expo [sic]. I expect the same to happen.
I was rather unimpressed with how they tried to steal Q-Con's thunder, and am not pleased with how they're trying to muscle in on two major comic cons. However, I think the reason is that MCM are not a non-profit org, like most gaming cons here (and, I believe, anime cons). So, they're treating this like a business venture, while we're treating it as... Well, an invasion, which it probably is. The fact that a main person in MCM is Irish shows that he/she didn't think comic cons in Ireland would be profitable, and didn't want to take the risk of finding out, but the moment someone else takes the chance and proves that they are, by damn, MCM wants some of that pie!