In my opinion, "Desktop Environments" are what we seek when we are used to a common commercial offering, such as Windows or Macintosh, and we don't want to read a book to turn the computer on.
But once you realize the extent to which everything is a config file, you start resenting the dictatorial feel of a "DE," and becoming less forgiving of slow, laggy, or buggy behaviour. If you think of your favourite window manager as a DE, you think "well it's pretty bare bones, requires a lot of configuring, but it's functional." If you think the opposite, of your favourite "DE" as a window manager, you think "what deranged mind designed this unweildy boehemoth? What is all this hardcoded insanity?"
In life, however, one must be practical. You can't dedicate time to everything, sometimes a "DE" is what will suit you best. Undoubtedly, all the opaqueness of it does leave it open for agenda injections. Top pretend otherwise is to be suspect, and I am pretty sure everybody who eventually switched to something minimal has experiences of noticing things about a "DE" that definitely is not a funcitonal necesity or even a luxury or asthetic improvement, it is simply weird code doing weird things.
People have all sorts of reasons for all sorts of things. The fewer avenus you leave open, the less they can arbitrarily inflict them on you.
Maybe more importantly, keeping things small gives your computer unbelievable power, the amount of resources that get freed up is ridiculous, and the comfort lost along the way is comparatively marginal. It's a pretty whacky resource economy, likely only possible because of the entry barrier to understanding more or less the3 hazy outline of what a personal computer does behind the curtains.
en.wikipedia.org
