Home Field can be an advantage, but it's never the only consideration. Ultimately, the games are played. It's decided on the field. Places like CenturyLink Field and Arrowhead seem to take fuller advantage of having the home field. But, that can only weigh so much. Fan support doesn't mean players on the field execute.
As far as this Wildcard weekend, the only game I'm surprised about is Washington losing at home. I thought they would take that one. I expected to the other 3 road teams to win. Houston just didn't have enough to compete with KC, thought that the Steelers and Seahawks being the hot teams going in that they would take care of business. But, both those games needed things to fall their way to come out with victories.
In any case, the Hawks play on!