Ok, I'll try and explain it better
As a club, there are things we can control, and things we can't control. I think the things we can't control have a huge bearing on our results, but I don't see there being any point in Martinez getting the bleach out because of those things.
I don't suppose that the things we can control have changed much between this season and last, so why should Martinez change his style in interviews? If he's preparing the side as well as he can and results aren't going our way for whatever reason, what is it we expect him to say?
For me, positivity is only a problem if Martinez is blind to any faults that exist in how the team is prepared each week. He may well be (and it's common in most of us to be honest), but I'm not sure we can really say that with any certainty. People seem to be getting mad because they're assuming positive interview = ignorance of any faults. I'm not sure we can make that assumption.