The problem I have with wordpress - and any php project for that matter - is that I'm afraid of the code. I've done some template editing for WP and it already scarred me enough.
But maybe I just prefer writing and working in my own familiar codebases instead of spending a small amount of time in that of others, a curse that a lot of PHP developers have (the "I'll write my own framework / cms" curse)
Consider though that when its template system was "invented" there wasn't much else available and people back then used to mix code and html all the time (both PHP and ASP developers). In their attempt to keep it backwards compatible we still have to suffer through the template system.
But maybe I just prefer writing and working in my own familiar codebases instead of spending a small amount of time in that of others, a curse that a lot of PHP developers have (the "I'll write my own framework / cms" curse)