I develop my web applications using only PHP for the view files and I don\'t feel limited in any way, but I hear there\'s a consistent number of developers advocating \"external
I use my own "template" engine, quite basic stuff, assign value to [key] and the sorts.
When I first looked for a template engine I found smarty, but it had so many security problems I ended up writing what I needed myself.
You ask why ? because it has many features that can make your coding faster (stuff what you didn't think of and stuff you can delegate to the template system instead of your code)
The majority of coders out there have chosen a template system and when working in a team you need to keep a standard.