I don't know what problem people have with "public opinion".
Do these individuals not realise that they are part of the public? That public opinion contains their opinion? That public opinion is an amalgamation of all of the individual opinions?
Football clubs make their money from public opinion, supporting a club is an opinion, in your opinion it's worth spending £600 on a season ticket. Or in your opinion, it's not. In your opinion £100 for a kit for your niece is worth it or, in your opinion it's not. Either in your opinion it's worth seeing that Snapdragon logo on the front of our kit twice a week, or it's not and you never realise that they are probably manufacturing your next phones cpu.
How could an organization, which is an entertainment business, not be swayed by public opinion?
Or is it that these posters believe that only their own opinions should count?
Even the public who aren't Manchester United fans have opinions that matter. It's those people who will be singing the chants that will be picked up live TV, it's those people who will bring up Greenwood every time we do anything good or have a moral outrage for any other thing.
There would literally be no Manchester United if there was no public opinion about them.