"Par is the score that an expert disc golfer would be expected to make on a given hole with errorless play under ordinary weather conditions, as determined by the Director"
-and part of that definition is "as determined by the director", not "as determined by math"
-who is an expert? and if you're basing who an expert is on their rating, then there's no point in all this computation, you should just use the PDGA's standards.
-what constitutes an error? If you hit a tree and get kicked next to the basket, is that an error? If you chain out an ace and the disc then rolls out of bounds, is that an error?
This definition is EXTREMELY subjective, and therefore a terrible starting point to determining a par standard. Especially when the PDGA already has a much more objective standard already:
https://www.pdga.com/files/par_guidelines_may_2017.pdf
Also want to add (as I'm sure others have) that deciding whether a hole plays closer to a par 3 or par 4 is completely and totally pointless. It doesn't make the hole good or bad, and it doesn't make it more or less legitimate. From a statistical standpoint, the only things that matter in separating good holes from bad holes are (and this is just my opinion):
1) Having a decent scoring spread, and most importantly
2) having a high correlation between a player's score on that hole and that player's rating.