In this case, you are probably just using classes to emulate namespaced functions [1], the use of 'class' is confusing to oop programmers, the code does not have classes, just the word class.
Like php code, php itself is often confusing and hard to decipher, currently I think it of it as a C dsl for web stuff that people mistake for a high level application framework.
Like C, many people learn basic syntax and functionality in school or as a side project. Unlike C, people believe that that their skillset is the one required to build a complex server side application combined with a web ui.
If you realize the mismatch and account for it, you can build great php websites. The problem arises when people assume they are getting a 'faster/cheaper' .Net/Java stack and start to hire programmers into that structure.
The net result is a clash between people that are using PHP as intended, and people that have been subjected to the misuse of the php.
1. http://stackoverflow.com/questions/5647598/cannot-import-use...