Agree, breezy. Yet, how many do we see performing with their eyes shut (concentrating to remember lyrics, most probably). That means that a) they cannot use full body language in the delivery of the song (otherwise what use is a live performance), and b) the cannot see the punters' reaction. Just listening to the applause at the end is not enough to judge reception, as our personal "clapometers" tend to be calibrated to show a better result than the truth; we're only human.

A lot of folkies believe, wrongly, that to be esoteric and introverted in the performance shows commitment and true depth of feeling. B******s to that, they're deluding themselves and boring the rest of us.

So, all you introverted folkies, all together now, sing along with me: "I will communicate with my audience, watch their faces and adjust my performance". Repeat 1,000 times.