It seems to me that any experienced PHP developer could write their own template system in just as much time as it would take to learn someone else's (like Smarty).
Why would any experienced PHP developer use one of these things?
Smarty is really not that hard to learn and it also includes a ton of great feature that would take a long time to develope...
In general templates are intended for non-PHP developers. The sort of folks who are good at laying out the site but not so hot at programning. Real developers of course program in c and write apache modules.
