When incentives reward casinos over products, even talented builders end up optimizing for the wrong game. That lesson applies far beyond crypto.
There are builders and there are opportunists. The builder's goal is to build something useful. Often the most useful things that you can build are not going to earn you a single dollar, but a builder will still go ahead and build it.
The opportunist is just trying to make personal wealth, which could come from the pockets of end customers, or investors, or other speculators (the "greater fools").
A lot of people made a lot of money from crypto and blockchain, even if ultimately almost everything built in this ecosystem is inconsequential trash.