You called it proselytizing.  Your assumption.  You don't know me personally; so, I'll let you have your assumption. 

Bob gave you an answer that was somewhere between over-the-top and off-the-wall.  You responded with a question, and he gave you a literal answer.  If you didn't find the humor of it all, I'd let you have the not-finding, also.

I spent the time deciphering the answers given by Bob and @sjrcpa, with a tax practitioner's perspective.  I thought my answer was technical enough for addressing your original question.  You just came back to complain.  Yes, I did continue on with Bob's line of discussion.  I'm chatty. what else can I say?  If I quoted a movie line here, would you say I'm advertising for Hollywood?  If I quoted the lyrics of a song here, would you also think it's unprofessional?  I just wonder.  

Personally, I'd say there's a big gap between the discussion and "proselytizing".  But that's me.

As to "Anyway to stop it?"  The short answer immediately came to mind: No.  Literally.  

Source?  None.

Billable hours are calling, and I digress.