The hard sciences also have a lot of people for whom English is a second language, and that can come out in odd ways in their writing even when they're completely fluent in speech. (One that stuck in my head from my lab days: knowing when to use "a" versus "an" in front of an acronym that starts with a consonant whose spoken name begins with a vowel.) I think my brother does a lot of editing for his friends on that basis (in his case for free, or for whatever random assemblage of pizzas and help moving you get in the grad-student barter economy, but that doesn't mean that there's not a market).