@Gumbo72203 said:
"But what I fail to understand is their reluctance to chase this majesty on a nightly basis, when they clearly simply have to try, and they will generally succeed. "

Here's a quick analogy before I go break the news to my wife of 20 years that I "accidentally" got SPAC tickets after hearing Mansfield tonight:
She and I have been married for about 20 years. 3 kids, yada yada. During our relationship, we've had some amazing, transcendental sex. We've also had times when we've gone through the motions. We've had learning curves, hot streaks, doldrums, you name it. You know what doesn't help get back to the magic? Dwelling on who is just putting in a "perfunctory" performance. Doesn't help me, doesn't help her, doesn't help US.

Now, 20 years is a long relationship for 2 people. Imagine 30 years and 4 people! Throw in an obsessed audience? That's insane! I have to say, if you don't understand the "reluctance" to chase "majesty" every night, you need to have a little perspective.
Check it out, see if this helps. During Free at Clifford Ball, I don't know what in the world happened to me when Trey was doing that airplane climb and dive business, but I sure as shit want it to happen again. During the Light Jam at MPP II last year, those stops and starts, calling back to the It's Ice jam from the 1st set; I got there again.
When was Clifford Ball, Aug 1996, right? MPP II was July of 2014.
Those are just 2 examples of many many many simply amazing experiences over the course of my experience with Phish, and they're 18 years apart. I give Phish AND myself a lot of credit; they didn't turn into some nostalgia act, and I didn't turn into a tired old man. The 'majesty' is not just simply manufactured. It takes 4 band members to be feeling it; plus I have to be in the right frame of mind, plus a little luck with the venue and my immediate surroundings, and then we've got something! No disrespect intended, but if you imagine that the band COULD take me home to Jesus at every show, but they just don't feel like trying, this, I think, is EXACTLY what the OP was identifying as chapping his ass. And it's tough to have great sex with a chapped ass.
See ya at SPAC, cuz my wife is sooooooo fucking cool! :-) Let's hit the road and have some fun!!!!