The year we were 1st in the nation in FTs attempted and 2nd in makes they were having routine fits about our FT percentage. I tried to explain to them about the makes and FTr but they weren't having it at all.
If there is one advanced stat that "traditional" basketball fans do not get, its FT rate. Its like explaining physics to a frog.
If ADv people cared. They would make a stat called: PPG from FT or something. Then you could use it to show that it is correlated with FTR and not FT%.
To be fair, the ADV stats guru (Dean Oliver) estimated the FT rate portion of the four factors to be around 15% contributing to winning/losing. I think the points factor of FT rate is very important, but to me its much more than that. First, its a great indicator of the aggressiveness of your offense, ie. does your offense seek to attack the rim/get the ball in the paint or does it seek to mainly create jump shots. Second, a high FT rate puts pressure on a defense because it also correlates with getting your opponent into foul trouble which changes the way they defend you.
All that said, FT% still has importance. If you have a great FT rate like we did against No Colorado (55.9%) but only make 48.5% it becomes a detriment because you are "wasting" possessions. Same with the Ole Miss game, we had a fantastic FT rate of 65.4% (partially due to fouling), but only made 55.9%, so we made a game that should have been a comfortable win close. Against SD we didn't have a great FT rate (32.2%) and magnified that by only making 50%, especially by missing 5 of our last 8 attempts.
Also, this is where %PTs from 2s, 3s, and FTs comes into play. All of those games our %PTs from FTs was around 48% of our FT rate. I think in many games this percentage isn't a big deal, but in a close game your %PTs from FTs better be over half (52-55%) of your FT rate to maximize your FT rate. And the higher your FT rate the more important this ratio becomes because you are relying more on PTs from the FT line.