Why is an excess of pampering more detrimental than beneficial?

David Foster Wallace's "A Supposedly Fun Thing I’ll Never Do Again," the title essay in his 1997 collection of the same name, is a critique of mainstream American culture and the concept of leisure. In this essay, he recounts his week-long experience aboard a large cruise ship in the Caribbean.
In his view, for most of the passengers, "fun" means overindulgence. And for the staff working on the cruise ship, "hospitality" means excess. Food and drink is one of the primary excesses that Wallace highlights:

There’s never a chance to feel actual physical hunger on a Luxury Cruise, but when you’ve gotten accustomed to feeding seven or eight times a day, a certain foamy emptiness in the gut always lets you know when it’s time to feed again.

On this cruise ship, according to Wallace, there is too much food, too much coffee (he mentions his near-toxic over-caffeinated state many times in the essay), too much forced frivolity, and too many organized activities (what Wallace calls "Managed Fun"). The culture aboard the boat encourages indulging and taking it easy: none of the passengers need to exert themselves in any way or to think about anything. Everything is provided.
So what's the problem? For Wallace, the excesses turn him weak, soft, and spoiled—and unable to control himself:

I normally have a firm and neurologically imperative one-cup limit on coffee, but the Windsurf’s coffee is so good, and the job of deciphering the big yellow Rorschachian blobs of my Navigation Lecture notes so taxing, that on this day I exceed my limit, by rather a lot, which may help explain why the next few hours of this log get kind of kaleidoscopic and unfocused.

In other words, one cup of coffee would have been pleasurable. Four cups are too many, but there is no one to stop anyone from overindulging. Wallace talks about lying in bed "glassy-eyed" in the last stages of the cruise:

all through the next day and night, which period I spent entirely in Cabin 1009, in bed, mostly looking out the spotless porthole, with trays and various rinds all around me, feeling maybe a little bit glassy-eyed but mostly good—good to be on the Nadir and good soon to be off, good that I had survived (in a way) being pampered to death (in a way)—and so I stayed in bed.

Wallace was supposed to have fun on the cruise, but like most others, he is not self-disciplined enough to exercise restraint. And he doesn't like the emptiness of being without a purpose, of being unable to think properly (and, moreover, for having no reason to think about anything). The contrast between the cruise and his real life are beautifully summarized in the last lines of the essay:

subsequent reentry into the adult demands of landlocked real-world life wasn’t nearly as bad as a week of Absolutely Nothing had led me to fear.