All it takes is a few weeks of no signings. The fans just want buys buys buys all the time. The thrill of getting our business done early has worn off so people want more, when they aren't getting it there is negativity.
If we signed Otamendi now, people would be over the moon and predicting title wins. By deadline day if we hadn't signed Pedro..after 2 weeks of nothing, the same people would be predicting us 3rd/4th.
Then when the window shuts and we can't buy players, fans start to develop a little more reason.