In my experience, that’s not entirely true. Some of my mathematician friends claim that they (and other people they know) often rather read the source code than the type-set result. I’m inclined to believe it because the biggest problem with LaTeX (to me) is jumping between the source and the result while editing, especially when formulas are involved. (Syncing tools help, but they’re far from perfect.) So it is often more convenient to just work with the source but this leads to problems where mis-typeset formulas don’t get recognized because too little time is spend with the result and they look fine in the source. And then people start reading the source code of other people’s papers because it’s more understandable, making the whole thing absurd.