Yo Soy Anal Retentivo ( lol )

Hey, these are good questions. I remember this phrase as being one of the ones I filed away to address later (so no, I didn't get it either). You can find on the following page how it is used in other contexts (which also didn't help me):
https://www.linguee.es/espanol-ingles/traduccion/no+tener+por+qu%C3%A9.html

I remember being kind of sad when I hit the last lesson of Level 3 too - sort of like getting to the end of a good book. The Travelogue is my favorite course, btw. I highly recommend it.
 

Thanks, I appreciate the link.  I think I have to loosen up on my expectation for everything to be so consistent.   ( especially with verbs like dejar and quedar, which seem to have so many uses )

Hola uds.  This was confusing to me also.  I asked my wife.  It was kind of humorous watching her run the phrasing through her mind.  Here's what I noticed that helped her work it out.  It's not that por was added.  It's that que was replaced with por qué.  Notice the tilde.  Then she rephrased the sentence to No tienes razón para ponerte tan político.  

This makes the given translation a little misleading, although not incorrect, as it's really more about not having reason or sufficient cause instead of meaning having to.

My wife said that using the por qué or razón para phrasing emphasizes a little more the motive behind the action and in it's negative form, as this example, is used often in given correction.

You don't have any reason to get mad.
No tienes por qué (razón para) enojarte.

Hope this helps.

As far as level goes, I'm still in level two and haven't completed a lesson since my wedding.  lol

Yes, I see now.  That makes sense.   Totally.  Thanks.  Sometimes RS takes a slight liberty in the way they give you the English translation. 
IOW, it's not a literal translation.  So I was  overly focused on their english translation instead of just slowing down and looking at the spanish, and realizing.. yep, they are literally saying with this Spanish sentence:  You don't have the reason.
  I'll keep that in mind.
 

Very helpful as always, thanks Jeff.

I used to send in suggestions to RL to render the translations "more accurate". I was mistaken to do so as I'm finding that breaking with literal translations is actually much more helpful in the long run in becoming fluent. These courses are really well thought through.
 

Excellent!  I'm glad this was a help to you guys.  My wife has really helped (forced) me to step up my Spanish.