Lets be real, the creators people bitch about are making FAR more money than simply keeping the lights on as you are saying. Because we're in the Nyl thread I'll use him as an example, his patreon says 34k a month. Even if I assume he only takes home half of that, he is hardly living on white bread and mayo in a dingy basement apartment with a single lightbulb.
While some artists, like Miro as you pointed out, are for sure just milking this I think its far more likely that these people just aren't good at being self employed as far as productivity goes. I would guess that they go through a "manic" work phase and then get burned out. Setting a more regular schedule would likely improve their work life balance as well as their productivity. I know people hate management...but these people need a supervisor. They need to be doing an analysis about hiring people to offload some of the work and if that would benefit their bottom line. AgentRedGirl is a good example of this, hired a staff and puts out a long form vid monthly or so.
I guess to be fair, most of them probably don't really care because they know that once you get to a certain level of popularity you can pretty much coast from there and people will continue to pay them.
Also, to head it off before people say it: blah blah, I know its patreon/subscribstar, your just giving them money or whatever. My take is that its a shame that people don't take the business part of this as seriously as they take their art.
And now I've become a paragraph andy on a porn pirating website, sigh.