Individual dickheads' actions should affect the game just like good performances do, because football is a team sports. I think it more like, if one "dickhead", as you say, is in offside, the team is in offside, and then the goal isn't valid because the team made a mistake. Be it an individual dickhead or not, he is still part of the team.
Just like when some non-dickhead scores a goal, he scores it for the team, though he also gains personal credit from it. Well, whatever.
But the main point is however that it's easier for the linesmen to call offsides when there's less chances of error. By the old rule, they only need to keep theyr attention on one - the lowest - player at a time; by the new rule they sometimes have to simultaneously follow as many as four... perhaps even more players at some occasions. There are bound to happen errors more with this rule than with the old rule. And call errors being decisice to the result are not something we want to see. Therefore - a rule that make sless errors possible = good, a rule that makes more errors possible = not so good.
Oh, and about this particular offside call in question - I only saw it a few times slowed down, but it definitely seemed to me like the player in the middle wasn't on the offside. On the other hand, they were all in one big cluster and it was sure very difficult to linesmen to see who was where and who played the ball. And, by the old rules it would've been offside, simply and effectively. 8)
