[development] why not just phptemplate in core?

[Tobias Maier]

Hello,

I have one question.
Why do we ship a plain PHP theme in core?
Wouldn't it be good for consistency if all themes would be a phptemplate 
theme?
and wouldn't it be easier to maintain a phptemplate theme as a plain PHP 
theme?
Is there any reason why chameleon is plain PHP?

I think it may confuse people that we ship a theme where the code is not 
similar compared with all other core themes.

cu Tobi

btw. I converted the chameleon theme to phptemplate:
see http://drupal.org/node/41005