Your analysis is reasonable. I suppose:
- Template designers and back-end programmers may not be one in the same, so it promotes separation.
- It protects you from yourself somewhat in that you can't really do "too much" PHP in your templates.
- It may be easier to optimise/precompile templates in some scenarios? (This is speculation)
Personally, I think they're more hassle than they're worth. Particularly they don't work if you want to hand
the templates to "designers" since the WYSIWYG tools don't know what to do with them.
