I think you're being intentionally dismissive at the cost of realizing that basic, essential waste management (at a small scale) is more or less a solvable problem for people who want to live nomadic lifestyles. Is it a tedious chore from time to time? Sure. Is a marine toilet the same as a open-top bucket full of shit? No (and something tells me you do, in fact, know this to be true).

Here's the reality. People choose, sometimes, to live aboard a moving vessel - either by land or by sea. These people take an audit of the pros and the cons, and they decide that dumping out a compost toilet once a day (if that) while the coffee is brewing is worth the benefit of living in nature or at a low cost, or whatever their bigger rationale is.

What you are saying is basically: "Oh BROTHER! You thought you'd like to have a dog? Good choice, nimwit, bet you never considered they have to EAT and POOP and be TRAINED." The fact is that most dog owners enjoy the companionship so much that they actually have no problem taking on these chores, because the positive outweighs the negative. Of course no one enjoys picking up dog shit, but it's a price to pay and it has to be done, so most of the time good people who like dogs do it.