sometimes it's hard to tell what they're hitting. other times it isn't, and they're hitting targets that are obviously military in nature: hangars, barracks, etc. some of the targets seem to be farms, and are likely covers for something else.
you see the same thing in syria. these targets were not built by isis - they're often clearly several decades old, and often clearly military in nature.
so, what are they actually doing? are they purposefully abolishing the military infrastructure in these countries? and why?
the easy way out is that they've been taken over by isis. but hangars and barracks in the middle of nowhere are not exactly strategic for a group without aircraft that seeks to control the transit points. you could probably find me an example where this is true, but the claim that this is true, generally, is rather dubious.