[development] why not just phptemplate in core?

[Khalid B]

> Plain PHP themes are useful. Correct me if I am wrong, but I do not see
> a way for a PHP template theme to control what features it offers or
> which block regions are present. As far as I know the only way to
> control these is in a plain PHP theme.

PHP Template can show a specific region anywhere you like.

You can do it using flexiblock:
http://baheyeldin.com/drupal/drupal-using-flexinode-to-show-hide-adsense.html

Or using 4.7 regions (which is more tedious).
http://baheyeldin.com/drupal/using-drupal-4-7-regions-to-show-hide-adsense.html