It doesn't sound like mocking scams, it sounds like mocking people not putting money where their mouth is. A lot of people already promoting "defi" are keeping their funds on centralized exchanges. Why? They still provide a performance edge and more features, but if all you need is basic trading, they should be being utilized even more.

DeFi has no fiat gateway though, that's the biggest bottleneck. The gateway is the centralized exchanges, and I think people tend to park their money on them once they deposit/convert their dollars.