Is there some actual self-consistent, generalizable model behind what you're saying that improves my ability to think about ethical obligations, correctly rejecting or accepting some of them, or were you just signaling there?
Or don't, but don't pat yourself on the back for not doing it.
The question was how the random point about maids relates to the rest of your original comment, and why I'm supposed to throw cash at everyone I come into contact with who's doing their job (as suggested by the original responder), not "how does tipping affect wages?" or "how do I get cash?"
It didn't answer my question to tell me that they're underpaid. 
Second, the existence of the tipping expectation dynamic does not "seal the deal" here: it's well known that there is a large group of people who have no idea that "it's a thing" that maids get tipped. If you want to fight against the tipping system, this is exactly the situation where you should do it, where tips aren't reliable anyway -- just like tipping for takeout or at food trucks.
Finally, I really dislike helping people evade taxes at my expense.
I entered this thread thinking that people who confidently gave advice were familiar with the relevant dynamics and that I could learn from hearing their worldmodel. As it turns out, the responses are just repetition of what I already know (with condescension and moralizing), in a way that doesn't answer my questions. Fool me twice, shame on me. It was really too much to expect that someone who told me that I should tip "too be nice" actually has a self-consistent, scalable model to back that up.
 Remember, "underpaid" is not the same thing as "paid less in expectation of getting tips"; lots of jobs are characterized as underpaid irrespective of tips. You're not supporting the original responder's argument by repeating the obvious tipping dynamic; you're making a different argument.