I am no Wayne Rooney fan first of all, in fact I would go as far as saying he is a rather odious individual, so the fact that even I think he has been harsly punished by UEFA should say a lot to you. Rooney kicked out, yes, but it was a pretty mild act. If that was an Arsenal player then I'd have said it was a very harsh red card and arguably it should have been just a yellow. Rooney wasn't helped by the theatrical reaction from the defender.
If you watch the 'kick out' in real time it really is a very very mildly violent act. Even if you accept it deserved a red card then he should have only got the standard one match ban. The fact that UEFA have increased this ban to three games and labelled it an 'assault' is utterly pathetic and incoherent.
UEFA are much like the FA in many ways, they are an unaccountable bunch of biased tossers who like to perpetuate their own vested interests and their victimisation of Rooney proves this. Rooney is an idiot but his little kick out does not deserve a three match ban, this is not fair and it is not proportionate.