A lot of typewriter conventions come from typesetting conventions. People used quotation marks instead of italics while using a typewriter precisely because it was commonly done in typesetting too.

Also I think the number of boomers using word processing programs in the 70s and 80s was probably very small. Maybe an actual one can weigh in but my my dad was born in 1947 and we had computers really early, but he still used his typewriter for most writing and we didn’t get a word processing program until the 90s.