I don't fault the fighters for trying to win, it's the fault of the organizations and commissions for not getting the scoring correct.
If a round is close, and a takedown secures it, why not? You'd be dumb not to do it.
Takedowns alone are incredibly overvalued in terms of scoring. A takedown is exploiting a weakness in your opponent's defense, of course, but so is squeaking a jab through a good boxer's guard. And those things should be scored about the same. A takedown on its own is at best equivalent to a significant strike landed.
Now, if they use that advantage to go for subs or deal punishment on the ground, then sure give more credit for the takedown, just as a 4 or 5 punch combo that leaves the opponent reeling should be worth more than 4 or 5 independent strikes that don't do much damage.
Ground control should score highly (wears down the opponent, usually leaves the top fighter in a position to attack and the bottom fighter in a position where they have to defend), but the takedown on its own isn't any more valuable than landing a strike, and the scoring should reflect that, but currently it does not.