The marginal revolution happened in economics and a lot of those problems disappeared. A lot the things they couldn't explain suddenly could be using marginal economics and subjective preferences.
Marx simply didn't have the modern tools we have now. In fact if he was around afterwords it is likely he would never came up with Marxian LTV.
Frankly the only reason for it's popularity now, is because of it's association with communism. It provides the moral basis for it. As a result you've had a lot of people desperately trying to get it work in modern economic models as well without much luck.
But you can critique market economics using marginal theory of value. It just means markets have failures, not they are morally wrong at the core.
My own view is that the entire value discussion is tremendously muddled, confuses multiple issues, and is used to justify or support any number of spurious or specious arguments, generaally over policy.
The marginalists mistake price for value. Most orthodox economics does likewise.
Using the rational model somebody will only purchase something when it's price is below how much the person values the object.
It's related to consumer surplus. To make it measurable we use money as an approximate judge to work out much somebody values it. But the market price and how much somebody values something are different things in marginalism at the core.
But yes, costs, price, and value are three distinct, though connected, concepts.
I hate the term wealth creator as well. But it certainly is possible to create to wealth. If you take things that people don't value that much, use them in a way to provide something that people do value. You have created wealth.
In much debate and discussion I see "market value" substituted for "value". Often the implication is a vague one, as withmuch equivocation. pg's argumentventures there.
Keep in mind that Smith, Ricardo, and Marx each commit this error, including in the Smith passage I quoted. So do the Marginalists, or at leaast most of them.
Mariana Mazzucato may be an exception. (I've just discovered her, still going through her work.)
https://www.ted.com/talks/mariana_mazzucato_what_is_economic...
There couldn't be consumer surplus without it. I don't know how you could be marginalist and believe market price = value for user.
-- Adam Smith, Wealth of Nations, Book 1,Chapter 5 https://en.wikisource.org/wiki/The_Wealth_of_Nations/Book_I/...