This is true for the most part. For example, 99.9% of jazz fans criticized him last season for playing Millsap and Jefferson over Kanter and Favors. These fans have a lot of egg on their faces at the moment.
Examples of strawman arguments against Corbin that have been thoroughly debunked:
--Corbin is rigid and doesn't change lineups. DEBUNKED
--Why doesn't Corbin start Jeremy Evans? This once strongly held populist opinion has completely reversed.
--Why doesn't Corbin start Burks at point guard? We now know Burks has no pg skills and can barely advance the ball past half court on time.
--Why doesn't Corbin try different pnr defense? This argument reversed completely the moment it was found out that Corbin changes pnr coverage all the time. Then the board went into frenzy finding a way to blame Corbin for doing exactly what they were calling for but weren't bright enough to notice.
--Corbin doesn't understand NBA offenses. This one is the most telling of general fan knowledge. It's absurd to think a coach can with over 40 games in the NBA without understanding modern offense. If you can't teach offense then you can't defend, and if you can't defend then you can't win 40 NBA games. But no matter how ridiculous it was, fans were still know-it-alls about it.
--Corbin doesn't game plan and change looks based on opponent. The changes in the Houston game are just one of many exhibits, but the Fire Ty crowd weren't able to recognize any of them.
The list goes on and on, with most strawmen easily substituted for Sloan and crew and the same "fans" repeating the exact same arguments. Most fans exhibit Dunning Kruger Effect -- not smart enough to realize how dumb they are.