This is the main strength, and also one of the most obvious flaws, of PHP. What makes it incredibly easy to get started (if you start from static HTML) also makes it easy to trip yourself up later on.

Mixing logic and your text/data will work well for inserting a simple date, but when you start adding more complicated logic it is easy to create a mess which is difficult to read and modify even for you a few months later. That's the reason other frameworks/languages try to give you a more structured (and complex) starting point.