Steve, as a terrible typist myself, I don’t agree that the misused apostrophes are typos. Typos are hte for the, adn for and, etc. I have done that, but in my entire life as a terrible typist, I have never written a misused apostrophe. Nor have I ever seen it before joining FR.
To write rally’s instead of rallies is not a one letter error, and furthermore, it takes slightly more effort on most keyboards to access the apostrophe than an S. It is easier to write Nazis than to write Nazi’s, easier to write the Obamas than to write the Obama’s - yet a majority on FR do not know how to make a plural.
I recently made the specific type of error you mentioned and I am well aware of the difference between the plural form and the possessive form of a word.