Centralization is just too convenient for most people. Most people - technical or otherwise - won't accept the slightest quality-of-life (edit: and network size/activity) hit in exchange for the greater robustness of decentralized options, regardless of the application.

Note how the vast majority of people who use or interact with cryptocurrencies converge around a few centralized options. Even a ton of the technical people who develop cryptocurrency-related systems do.