I find it very frightening that the players of today don't seem to have the natural respect for the club, the badge, the shirt, the fans. It seems it's more about the tats, the hairstyle, the ear rings, the sun glasses, the cars, the big ear phones and so on. Makes me sick actually!
The Brighton display wasn't worthy of United. It's fair to lose a game if the players have performed up to their best - or at least tried their best. But when players don't care or come unprepared physically or mentally, that's another story. And sadly that's the story these days. Or at least in my opinion.
Don't think you can put the blame on the manager for such lack of professionalism, but then again... at the end of the day, Mourinho is responsible for the result(s). So if he can't get the players to perform their best, he has to go. That's a given. No matter who's to blame.