Elias Isquith examines it:
It’s true that the House didn’t move much, but as many have pointed out, this is almost entirely a consequence of the redistricting triumphant Republicans engaged in — as they had every right to — after the 2010 election and in light of the new Census. Look at the raw numbers and you’ll see that Democrats garnered roughly 500,000 more votes than their Republican opponents. Not a landslide by any means, but a number that goes unreflected in the actual Congressional results.
Dylan Matthews believes "redistricting could keep the House red for a decade":
[I]t’s going to be tough for Democrats to make big gains in the House until 2022, when the districts are drawn again following the Census. And for that to happen, they’d have to do quite well in the 2020 state legislature elections.