I think it is deeply unfair to lay this entirely at Feig's feet. If you ask me, the buck stops at the studio C-suite.
Feig never really was that interested in this film to begin with. So, right off the bat, you have a director who's lukewarm on the project. Then they tell him he can do whatever he wants...so he just does his usual Feig film -- which is
exactly why they hired him in the first place.
If you say "Go make us a Paul Feig movie with the Ghostbusters IP," and the guy does exactly that, you can't then get pissed when that's exactly what he gives you. Basically, if you hire a contractor based on their reputation, and say "Do one of your things, just with some of my stuff," you can't then be pissed when he does just that and the public doesn't like it.
And none of this mentions how Sony and Feig himself handled the pre-release marketing of this film, which was...
--EDIT--
On a related note, I am disappointed at how this whole project was handled. There was never anything wrong with an all-female Ghostbusters film in theory. There WAS, however, something wrong with a half-assed C-suite-driven reboot that tosses out the old continuity on the theory that you can just slap a brand on top of any old film, cast people to hit "target demographics," kick it out the door, and rake in the cash.
Certainly not with a $150m budget, anyway.