Part of the reason is internet commentators are so mean to each other, and many of us users don’t want to be judged by someone? (Although extreme echo chamber is also a bad thing)

Thank you for this valuable information.

Isn’t “have” either an auxiliary verb or verb and “of” a preposition?

Are these acceptable? If yes, why? If not, why not?

• I of heard that story before.

• Diane of already gone.

• John ofn’t phoned, of he?

• I ofn’t visited London before.

• Of you seen Roz?

• Of she been invited?

• They still ofn’t of any news when I spoke to them yesterday.

I don’t know man, Oxford Dictionary (click Grammar Point to expand) says that https://www.oxfordlearnersdictionaries.com/definition/english/have_2

A common mistake is to write ‘could of’ instead of could have or could’ve

I could of told you that.

I could’ve told you that.

The reason for the mistake is that the pronunciation of ’ve is the same as that of of when it is not stressed. This is a common error but it is definitely considered wrong in standard English.