I think it's a bad habit worth stopping and I'm trying to do just that.

The involuntary reflex of a fly-away finger means to me that I have no control over said finger, i.e., it's not doing what I want it to do. That it's difficult to correct means that I have trouble controlling the finger, i.e., telling it what to do. That's not good. Further, when the finger is high up and stiffly pointing up in the air it's not ready for a quick note...it's not near the string and the fret it needs to play. That's not good.

I was at a John Prine concert which had a Canadian duo open for him. The duo was quite good but the guy in the duo had a fly-away finger and it just didn't look professional, harsh as that may be.

I sometimes notice that my index finger also points to the sky depending what chord I'm playing. That's not good either. Yeah...I believe finger independence is a good thing and something to aspire to and I'm trying.

It seems to me the video has a lot of general, common sense commentary. I don't know if I buy the idea that particular exercises are not the way to help rid the problem. Maybe because Justin ( justinguitar.com ) taught me this one...good for flexibility, strength, stretch... and even finger independence. ;) It'll also lock in proper technique (e.g., vertical, arched fingers and hand parallel to the neck) when practiced properly.
http://www.justinguitar.com/en/TE-007-FingerStretch.php This exercise accounts for over an hour of my weekly practice time.