I agree entirely with the premise that WordPress is not the most impressive codebase in the world — but that's not why people select it. The reason that sites

I agree entirely with the premise that WordPress is not the most impressive codebase in the world — but that's not why people select it. The reason that sites opt to use WordPress is that the editorial interface is familiar and the plugin ecosystem is very robust. The reason that sites stay on WordPress is that upgrades arrive for free every couple of months and do not break backwards compatibility. WordPress's performance has improved over the years largely as a result of the rising tide of CPU and RAM upgrades and improvements to PHP and MySQL themselves — and more recently through integrations with Elasticsearch, which WordPress works particularly well with. It's also possible to use WordPress as a framework and to develop elegant code using its APIs, which is largely what my firm does (I run one of the handful of agencies that partner with Automattic to provide WordPress consulting to big companies). But that's the exception, not the rule, and most of the prospective developers we interview who have WordPress experience can't use it the way we want.