I would agree that ju-jitsu does dominate UFC, but do you not know that Aikido and ju-jitsu have similar roots? Aikido has been adapted to reduce injuries of your opponent and to enable full contact without damage. However, there is definately an argument for making some Aikido clubs have a stronger martial attitude.
Also, if UFC is no hold barred, what happens when someone comes in with a knife? Or what happens if there are three people attacking one. What do you mean that doesn't happen?, it does in real life, and although a wrestler might be able to take someone to the ground and choke them, he won't be able to do it if his bowels are littered across the floor.
P.S. don't take the responses harshly, you've obviously touched a sore point for Aikidokas; but train in the right manner for enough time and you'll realise that Aikido is very realistic (I have used it many times from both armed, unarmed and multiple attacks and I wouldn't be here today if it wasn't for Aikido).