The micro-level counter-examples you provide for macro-level mechanisms simply don't work.
If you consider your first example at a market level, people that are better compensated are more valuable—because they create more value (the discussion is—of course—not around one's value as a human being). The only reason for imperfection in this regard is market friction—which there is a lot of, in every market. But the market value tends very quickly towards the real value if the market is liquid enough.
In a liquid equity market (stock exchanges for example), the price of the stock you buy is its current value. However, you are making a bet on the future value gains of the company. Buying stock for its current value is investing; anything else is speculation.
If you consider your first example at a market level, people that are better compensated are more valuable—because they create more value (the discussion is—of course—not around one's value as a human being). The only reason for imperfection in this regard is market friction—which there is a lot of, in every market. But the market value tends very quickly towards the real value if the market is liquid enough.
In a liquid equity market (stock exchanges for example), the price of the stock you buy is its current value. However, you are making a bet on the future value gains of the company. Buying stock for its current value is investing; anything else is speculation.