I'm assuming you meant "At its core, PHP is just a template language." That's a ridiculous, extremely over-generalized assertion.
I don't know of many "template languages" that treat classes as first-class citizens, has an in-depth, thorough unit testing framework, traits, closures, and and and.
I'm sure you get my idea? PHP may have been much simpler at its inception - it is not the same beast now.