Precisely because PHP was always used and is still used in the front-line trenches of the web where business needs are always the #1 concern. Its used by small to medium businesses, professionals, individuals to run their businesses, communities and so on. There isn't any room for overoptimization, there isnt any room for wasting the non-existent VC money in developing questionable features, there isnt any room for any complicated setup that could cost time, which actually means money.

For that reason its also the most successful front of Open Source where an actual thriving ecosystem was able to develop on it through freemium business formats like in WordPress ecosystem. The plugin ecosystem of WordPress was estimated to have $1 bn volume a few years ago. And its quite streamlined in providing software and services at scale to the point of providing ordinary users and small businesses with features at price points they would not hesitate to pay. It does constitute an example for the rest of the Open Source world could follow or at least learn from.

Was hacky. It's awesome now.