Right there with you mate. We share similar views. I think some in here aren't comfortable talking tactics or don't see poor tactics as the reason for these poor results. A large part is how you view the game.
Some of my mates take it from "this is how United are under Fergie" approach. They'll mention my griping is pointless as Fergie has put out strange selections before only to settle on a team in the second half of the season where United really come to the fore and that he usually gets it right in the end. We've had a poster on here already dispel this myth about a major improvement in performances in the second half of our seasons recently. It used to be the case mind. They're right though, Fergie more often than not does get it right in the end.
However, they're not really comfortable talking tactics and whenever we play poorly, it's because we were either too slow to make a change, "bad day at the office", "one of those days", "team was good enough to win", "Fergie knows what he's doing", "opponents being game raisers" with that last quote being the most infuriating. Spurs didn't really raise their game against us, they simply exploited our lackadaisical play and the gaps we left exposed in the middle but I digress.
Main point is people see what they want to see and if their opinions are that strong, it's very unlikely they will agree or acknowledge your point, no matter how correct it is.