Booing a performance rather than individuals.....what's wrong with that ? Don't buy this "oh no, you can't boo, it's wrong, you should support the team" is ******** when you have sat through 90 mins - 180 mins if you were at the Wolves game - of the most turgid, clueless load of crap from professional footballers.
The booing when MP took off Gabby at 2-0 down instead of giving him help was correct as well. MP got that wrong without question.