Your claims are incorrect.
The PRSI is not a focal point of MacRumors, but is provided 1) to allow political discussions that otherwise would bleed into other forum sections, and 2) as a courtesy to users here who enjoy discussing politics, religion, or other social issues.
Reason 1) has to do with experience and a prioritising of moderator resources.
The decision not to have posts in that section count toward post totals has to do with the fact that the forum is considered an "extra". The decision has nothing whatsoever to do with devaluing the users who use the section or those users' opinions. Users who are very interested in politics might well choose another, politically-angled site for their discussions, but it's also a fact that users who have a tech and/or Apple interest in common might like to discuss other subjects with each other, as well.
The point that was brought up earlier about likes "counting" in totals but not the number of posts, is a good point. It's a software limitation, not a choice on our part.
As has been mentioned, there are differing opinions backstage about whether or not the section is worthwhile. Generally speaking, it's a good thing the staff has differing opinions - that's what keeps discussion good. Speaking specifically, and speaking for myself, I can see merit in the arguments on both sides. And at the end of the day, it's the site owner's decision.