A lot of software developers are are also business people. They focus and make decisions based on the needs of the organization, given the local job market, current staffing, past investments, the future roadmap of whatever product they are working on, etc. If PHP is the best route, then that's not something a business person is going to spend a lot of time worrying about.

In many ways, if a "coder" comes in and starts wanting to change a bunch of things purely because they are opinionated about languages, then that person is not going to go very far.