I think you guys are over assuming here. I mean, mizing flourishing and magic isnt necessarily a bad thing. TheBlack&WhiteIllusionist's example involving an ACR is obviously chosen to prove his point. See, the strength of an ACR is that it's essentially moveless. But just because flourishing doesnt strengthen one trick doesnt mean that you shouldnt ever use it. Just as it hinders the ACR, it may improve other tricks.
As with any move or sleight, flourishing has a place when and where it can be used effectively. I think most of us will agree that it's not always best to use the same top control, or same double lift. We should have options in order to use the right move at the right time. Just think of flourishing as one of these moves.
Assuming that you guys still think that TheBlack&WhiteIllusionist's example proves the point completely, then, following the logic that one example can prove something to be absolute, here's an example that proves how flourshing can help.
Now I'm not a floursher by any sense of the word, but I do use it in this one example. Essentially a card is selected and top controlled. I then go into a series of fancy false cuts explaining how I'll give the deck "a few simple cuts". I then pull out some X indifferent card from the deck and confidently say "your card the *indifferent card*" as I get the "ahaha no." answer, i simply top change and play along. Eventually changing the card using various patter lines that convince them they saw it change cleanly.
Now lets go over how flourishing improved this trick. We're obviously looking at a magician in trouble type of presentation here, so in order to really accomplish that, we need to make them believe that we truely are in trouble. The confidence in which the cuts are executed and the cockyness of the "simple cuts" line really makes them go "my god, this guy knows what he's doing. He's great". To then have the card to be wrong, I've brought them up; heightened their expectations then crushed them. I've made them believe I was good before they thought i was bad. This increases impact because there's a larger change.
Had I just pushed out a random card, and claimed it to be theirs, I think we can all agree that it would be a strong effect, but not as strong.
So yes, flourishing can be used in conjunction with magic. It's just a matter of how you encorporate it. Also, make sure that if you're going to get into flourishing that you still take the time to practice both fields adequately. There's no point in picking something up if it's just going to bring your skill level down due to lack of practice. Don't spread yourself out too thin.
That said, I'm not a flourisher. I dont do flourishes. I can do a few little things, but nothing impressive to any of us magi. The only time i ever do flourish is when messing around with cards (and even then i generally go for other things then cuts) and in the example trick given.
Hope you enjoyed.
Cheers,
Lucas