Typos are great attention-getters.
Internet trolls comment on them. Print readers circle them in red pen. Journalists remember them (then discard the pitches in which they appear).
Right or wrong, readers hold professional writers to nearly impossible standards of accuracy and clarity. Spelling errors and grammatical mistakes steal the audience’s attention from an otherwise-compelling piece and undermine the integrity of the writer. In flawed pieces, the opportunity for clicks, shares and subscribers can be lost.