I came from the other direction. I fumbled my way through a lot of php (mostly CMS' like Wordpress), got the programming bug and came to Perl. One of the things I felt was that php has A LOT of built-in functions (seemingly more than Perl) for some things that I now don't find difficult to do. I think that's one of the reasons some beginners/web designers may find it easy to jump in to php; you can hack your way through it by plugging in built in functions rather than learning to actually program in it. *(Well, I'll just speak for myself there :) ) I don't know if that's good or bad to you, I simply feel now like it sometimes can be a little bit overkill and inelegant.

If you want to learn php, I would suggest subscribing for a month to Lynda.com and particularly go through the course taught by Kevin Skoglund who IMO is an excellent instructor. (His course on Unix command line for Mac OSX users is fantastic.)

UPDATE
Weekday, 16.Nov.2011 :: 8:02 PM ::	Expanded on the appeal of php for beginners/web designers.