I feel like there’s an underlying misunderstanding between two parts here.
Although I think the diversity sections were over divided in the OP (character, intention, and morals would all go under phisophical diversity imo), I do agree with OP in that diversity doesn’t only include race, ethnicity, religion, and sexuality (the most mentioned diversity classes on the forums, at least from my experience). If you look online for an extensive definition of the word, you’ll find that OP is mostly right.
I feel that the misunderstanding comes from the fact that most people would consider those added sections (character, morals, social class, etc.) merely as poor and lazy writing in case they were all missing in any given story. But since we live in a time period where some of the groups within the diversity umbrella are severely marginalized, people are going to notice the lack of racial, religious, or sexuality diversity in stories much more and are most likely to get mad and speak up about it. Not to mention, it’s much more likely that a story lacks ethnic diversity vs social status diversity, for example. This is what makes people mad 
Technically, overlooking the ‘’‘traditional’’’ diversity categories is just as lazy as missing philosophical, or education status diversity. Ideally, race, ethnicity, religion, etc. should all be a given in any story. We’ve just come to considering and treating them differently than other categories because not only is there a sever lack of them, but irl they’re also all oppressed classes.
All this to say, it doesn’t change the fact that OP is right, diversity as a term is much broader than that. People have simply started to feel strongly towards certain types due to societal issues.
Otherwise, I’m the one who misunderstood, in which case please educate me! 