There were a lot of curmudgeons (I among them) who were resistant to migrating to the 2.0 StackExchange platform. A major reason was the concern that community participation would drop dramatically, and another was that the forum culture would change for the worse. There were a number of minor reasons as well.
Fortunately, the forum has continued to this day ("But for how much longer?", as I ring my curmudgeon bell) and the culture changes have not been as drastic as I anticipated. I think hats run counter to the culture here and so advise against it. However, my presence has been tolerated here, so in the season of goodwill, I will grit my teeth and likewise tolerate an occasional hat. I don't know if it is possible to activate them here on MathOverflow, or how to do so.
Gerhard "Is Winter Bash Over Yet?" Paseman, 2016.12.23.