A successful takedown in MMA can show dominance in an MMA fight. But for it to truly be successful, I believe that a fighter should be able to either submit their opponent, or cause damage while on the ground. If a takedown results in nothing for a fighter, then I believe that it should be scored as nothing. If the fighter who scored the takedown could not keep their opponent down long enough to do damage, or they just laid on their opponent, then they should not receive any points for controlling their opponent.
In my opinion, a takedown that led to no submission or no significant damage, is the same thing as a submission attempt that led to nothing. The failed submission attempt does not score any points, so why should a worthless takedown be worth so much? This is why wrestlers have such advantage in MMA as of right now. They can win fights simply by laying on their opponents. This is not t say that wrestlers are not good fighters, but some wrestlers have a habit of taking fighters down and doing nothing significant from that point on.
If a fighter gets a fight to the ground, and then does not do any damage or get a submission, then how much of a fight really happened? I think that people are losing sight of the fact that MMA is still a fight. Wrestling is a part of fighting, but damage must be done after the wrestling aspect is over.
I think that takedowns are the biggest downfall in MMA scoring as of right now. They accomodate way too much to wrestlers and bigger and stronger fighters. I agree that controlling your opponent is a big part of fighting, but even if you are on top, if you are causing no real damage, you are still in defense mode as far as I am concerned.