Why use a templating engine with a framework?

Question

I recently discovered the PHP framework Kohana (which is awesome) and was reading a thread about using it in conjunction with a templating engine such as Smarty or Twig. My question is why bother? Surely an MVC framework, by definition, is a templating engine. Even "raw" PHP is, arguably, a templating engine. What possible benefits are there of adding another level of abstraction on top of what's already present in a framework such as Kohana?

EDIT - I realise that an MVC framework isn't the same thing as a templating engine, but surely the V part does the same job? Perhaps a better way of phrasing things would be; why add an templating engine on top of the V part of an MVC framework?

Answer 1

I have two really good reasons I can think of for doing this...

1. Creating markup that is repeated throughout the site in a consistent format is easier, plus you can update it later without a lot of grepping.
2. If this is for a real company, the people determining content aren't likely to be really familiar with HTML, much less PHP. Having a simple template language that keeps styles looking the right way and generates valid markup without much code knowledge is really handy.