Looking at some team stats today...
The pitching has been a bit unlucky so far. Their FIP of 4.38 and xFIP of 3.84 are both quite a bit lower than the ERA which is at 4.98. They've allowed a .317 BABIP (which almost always normalizes to around .300) and a HR/FB rate is a little higher than normal at 15.7%. Last year, the Astros BABIP allowed was only .285 (it's probably lower than .300 because of the use of the shift). Last year's HR/FB ratio was 10.9%. Things should get better, obviously.
The bad news is that they are getting hit harder than usual and at the bottom of the league in forcing soft contact.
Overall, the pitching will get better.