Of course they're playing a roll.
That people continue to feed by both extreme optimism and responding to their overt negativity. But that's beside the point to me. I feel that (and I admit, I skip a huge chunk of these threads...I don't have time for the bickering) the overwhelming positivity is starting to fade, but let's be fair - immediately after the season there were a large chunk of people thinking we were getting Mourinho and spending obscene money and were the new City.
It does not appear that was the case. The negativity rose in response to the bad Geordism (to steal a phrase) that was infecting this forum. I continue to have hope and patience. It's July. And I still believe that the players we have are talented - Martinez coached in a way that is anathema to success in England. Koeman seems to be less idealistic - which should be good enough to get us into the top half quite easily.
That said, we clearly need ins. Our midfield is weak. We have gaping squad holes - right back, left wing, striker, goalkeeper that must be filled if we're going to try for better than top 6. And beside that, we need someone to give the fans a lift after last season. The toxicity in the ground may not be fully lifted if we don't buy someone special.
The point you make is exactly correct - balance. Until something happens, we (except those that actually are ITK) should be a bit more balanced and patient in general. We haven't bought anyone yet. And it appears we did not get our greatest wish for manager (Mourinho/Emery...even if Koeman was first choice to begin with, he was leapt and ended up not being our first choice, in my opinion), or DoF (Monchi).
That doesn't mean we're doomed or everything has been awful...but you can easily see where the unease comes from.