Well, Jim,
Missspeling words like "sacrilege" and mixing up "forego" and "forgo" or "foreword" and "forward" is more understandable to me, and more forgivable, than using words like "it's" and "its" or "their" and "they're" or "who" and "whom" or other personal pronouns ("I" vs. "me") BACKWARDS.

If you ALWAYS used the same form - "it's," "me," "he," "who," etc. - you'd be right part of the time, maybe even half the time.
But way too many people end up writing things like
"Its time for every dog to be in its own yard,"
or
"Him and me threw a party for she and I's anniversary,"
or
"Who should I invite to dinner and whom should carve the turkey?"

I say if you can't remember when to use the apostrophes or don't understand the difference between pronoun cases, just pick one and stick with it.