I don't entirely disagree with the sentiment, but the example is so contrived. The problem with these sentences isn't that the word "just" and "simply" are some

I don't entirely disagree with the sentiment, but the example is so contrived. The problem with these sentences isn't that the word "just" and "simply" are somehow upsetting to the reader but that they're clumsy sentences. "Mailers are really just another way to render a view. Instead of rendering a view and sending it over the HTTP protocol, they are just sending it out through the email protocols instead. Due to this, it makes sense to just have your controller tell the Mailer to send an email when a user is successfully created. Setting this up is painfully simple." That said, I think there's rarely a good reason to say something is "simple" in documentation. Explain how to do it and let the user decide if it's simple.