Not in reply to anyone in particular.

Anybody interested in what Muncie has to say?

I was, so I called them. Here's what they had to say. (not verbatim)

1. No real science in weight/speed classification. More a simple way for a beginner or non-expert to pick an appropriate plane; either the airplane fits the criteria, or not. Because,

2. The park flyer program, even though experts and beginners alike are encouraged to join, is really focused on beginner pilots, hence, the Park Pilot Partner program, to help those beginners.

3. Although this wasn't said explicitly, my understanding of the conversation leads me to believe this program is an entry level stepping stone to, hopefully, full membership status.

I still agree with the OP that the limits might be a little high on weight and speed, but they are what they are and not likely to be changed anytime soon.