If you look at the volume chart here its pretty clear that the day before it hit poloniex around 80k coins have moved the owner: http://qcn.cryptostats.org/charts/volume
Before that the network was dead and nearly noone was even mining it - except some guy.
Theres no sell pressure yet on QCN because that dude doesnt seem to sell them yet.
I agree with your final point but not with the network being dead and nobody mining it before Polo. If your were around the IRC channel or even this thread before it went on Polo there were a fair few people mining it and trades were being done several weeks before hitting an exchange. There was also another exchange open before Polo.
dreamspark, are you talking about MRO (since you referred to this thread)? He's referring to QCN. MRO is much more evenly distributed.