The effort required to learn something better than PHP is not equivalent to learning everything about automobile engineering, its more like reading a maintenance manual. Sooner or later, the guy who fixes his car in the middle of the road without knowing anything is going to replace his brake-pads with bits of wood he found on the sidewalk (Not really his fault, someone on a PHP forum has already labeled all the bits of wood as "brake pads")...
A better analog than fixing a literal car might be changing the tire of a car which doesn't have any tires when it is parked but which instantiates some with the help of an instance of ITireFactory. Obviously it makes no sense for a car to use a tire factory instead of just having tires. That is exactly how everyone who prefers PHP feels about everything.
There are far better solutions to this ITireFactory problem than PHP, which puts the tires directly onto the car, but forces you to buy a new car as soon every time you get a flat.
Also, the tires are likely to explode every 16 left turns unless you know about the secret tire fixing button under the dash.
It is true that PHP may save people a few hours in the beginning, but at what expense? How longer does it really take to get a noob running a Sinatra, web.py, dancer or something similar?