THe ridiculous thing is, afaik Ivanovic got one for kicking the penalty spot, something that is truly awful and, having just found that out I'd like to see the penalty again. I had a huge go for Torres doing that against Utd iirc, I think its a truly cold, calculated nasty way to cheat. Ramires got his "in the aftermath of Barca's goal", first or second I don't know.
Basically neither were for last ditch desperate saving the game tackles, they didn't take them for the team and save a shot on goal, they didn't get unlucky with a bad ref who gave it for something stupid. It was just utterly stupid from Ramires and Ivanovic to get booked. However it's one of those things where, a very small minority of all footballers get to be in a champs league final(though those that do quite often get there multiple times), its a shame that they miss it, but then, what if Chelsea win and Bertrand maybe, who otherwise wouldn't have gotten a look in, gets to play his one and only shot at being in the final.
It's always unfair on individuals, overall footballers(more than fans usually) completely understand how team mates are involved even if they aren't playing in the biggest games. it will always be unfair on someone, keep the ban and that player misses out, let them play and their replacement misses out, let them play and the other team loses, its unfair to the other team.
ultimately, they broke the rules(and with Terry, Ivanovic and Ramires I have no real sympathy, all utterly stupid cards to get), so why should they play?
I think players should unquestionably, for the biggest occasions, have the right to have a board look at all yellows and red's and appeal/overturn them if incorrectly given. Because no one should miss out over a ref's mistake for sure, but apart from that, if part of getting to the final involved breaking the rules and punishment, had they not picked up said cards, maybe for a handball or whatever else, they might not have gotten to the final.