:People who are interested in Feyman diagrams are not the same people that are interested in everyday matters. It is a complicated subject and dumbing down is not necessary. You can read and use as much as you can comprehend. I think the language is pretty straightforward. I don't see any use in deleting parts of the article because undergraduates can't comprehend them. In fact not many if not nobody really understands quantummechanics due to its peculiarities that are counter intuitive. Anyway most of the popular books just show the diagrams and keep out the math because formulas are bad for sales. For Wikipedia this should not be a concern. If somebody has an interest in the Feyman diagrams he should be able to find everything about them here. Furthermore the english wikipedia is used by many people from many countries and the english article has to be a reference for the other languages. 

 It has to be noted that Feyman diagrams are not meant to honor the didactic skills of mr Feynman as is pointed in the article others have used that kind of diagram before mr Feynman.