'Takedown and let up' = buttscooting imo. They are both cheesy ways of avoiding the parts of grappling that you suck at. Both should be frowned upon because they demonstrate a corner-cutting, fast-track way to short-run tourney success. They aren't particularly sustainable in the long-run or against better competition, they just simply give you a chance to grab some quick wins using your opponent's and/or the ref's foolishness against them. The simple solution imo is to simply 1) NOT get up if your opponent disengages on the ground, and having the ref then decide who was responsible for the stop in action (aka. the guy who broke the action to get it back standing), or to 2) NOT engage the butt-scooter, and once again let the ref decide who is responsible for ruining the flow of the match (aka. the guy who flopped to avoid the takedown). These strategies should really only work with stupid opponents who are willing to play into your one-dimensionality or with bad refs who are too stupid to see who is ruining the match.
Now, that said, I definitely see a place for backing away and returning to standing if you find yourself in a bad spot (ie. forced to trinagle escape or armbar escape which then breaks the guard and leaves you on your feet) or from a wild scramble should you end up breaking contact with your opponent (ie. you should not be obligated to walk back into guard from a loose, uncontrolled position on the mat). That's a legit way to reset the action - especially if you're a good wrestler/judoka. But that is much different than a gameplan that is based upon not engaging on the ground. There is nothing wrong with preferring standing to bad positions on the mat, but there is something wrong with preferring standing to any and every position on the mat.