A professional editor/proof-reader with a passion for books and a love of reading that started with my first ever memory sitting on my mother's knee with a book.
Accused of being pedantic about correct grammar and spelling on more than one occasion, I believe that these are essential qualities for an editor with high standards. If someone is paying to read your work, then surely they deserve to have a good experience, rather than being distracted/misinformed by mistakes and errors. The English language is beautiful when used properly and this should be shared with your audience. An author's role is to create a good story or report, an editor's role is to ensure that the errors are found and corrected before publication.
If you don't want to advertise your shortcomings to the rest of the world, then please use a professional to edit your work and give your readers and experience to remember.