To be fair, as a Mac user I've only ever encountered that when using some rich text editors, but primarily word processors where your literal text isn't what you want (WYSIWYG editors). When dealing with plain text, even in browser comment blocks, it's always left my ' and " characters alone.

I think I've run across that in the wordpress editor as well.

Right, and, again, it's likely what you want 99% of the time (unless you're copy/pasting more code examples than prose). I'd be surprised if this isn't typical behavior of many blogging platforms.