Agree completely. The only honest way to make a living in a capitalistic society is to provide a service or product that someone wants. You can only make money by providing something people find valuable.
Yes, it's (approximately) true that the only way to make money is by providing something that people find valuable.
It doesn't follow, however, that if you make money then you must be providing something that is valuable overall.
Hypothetical example: I find a completely undetectable way to steal money from poor people and transfer it to rich people, except that 25% of it vanishes on the way. I offer my services to someone rich and unscrupulous. Although poor people don't have much money, there are a lot of them, and I am able to get my client $10M/year. She pays me $1M/year. (For some reason my method is only capable of enriching people who are already rich, which is why I don't just take the $10M myself directly.)
In this situation, I have provided something that someone finds valuable. It is unlikely, however, that I have made the world a better place (because of the diminishing marginal utility of money, etc., etc.), my actions would generally be considered unethical, and I wouldn't want to argue that I deserve all the money I'm getting that way.
(Some people would say that what I just described is the standard operating procedure of the financial industry. That may or may not have some truth to it, but all that matters for the point I'm making is that that general kind of thing can happen -- some jobs can be negative-sum but provide some people with enough benefit to make them well paid.)
Your comment's parent doesn't add anything to the conversation because it's a simple observation. I could add "I agree, people tend to spend money on things they want," and that would be valid.
But I haven't furthered the conversation because anyone familiar with the system of capitalism, i.e. everyone, knows this.
