I can't speak from any actual knowledge of the experience or show, but every show or festival I've every been to has a programming director whose job it is to keep these groups on their allotted amount of time; that's one of the two reasons performers always wear ear pieces (the other, more major, reason is to hear the band's blend better). Perhaps Red Rocks wanted them to perform that long? Emmy Lou starting at 10:30 means she would finish around 11:15 or so, which, while late, tends to be pretty average for a lot of the bigger festivals I've been to or heard about.

Regardless, I understand your disappointment. The last time I saw SCR they seemed less inspired than they were when they first started out, and their original songs seemed a bit bland. But I did really like their album North Carolina Song Book; lots of good and interesting stuff there.

Funny they talked so much, though; when I saw them (2015, I think?) they scarcely talked once in their show. I always enjoy some banter and introduction of the songs, but that's just a matter of personal preference, I guess. I can definitely see it being a bit overbearing if it's just flat too much, or if you're seeing them with something else in mind.