An interesting dilemma...
... that a high par can discourage players because it makes it more difficult for them to break 80 or whatever number, but then again courses with an unusually low par struggle to gain acceptance, e.g. among developers, because of the par-72 fetish, the desire for the "championship" label and so on.
I once designed a par-37 nine-hole course at Geysir in Iceland. Two par-threes and three par-fives. It simply fit the land. The terrain gave us a 420 m long first hole. I deemed that most players would have more fun playing it as a par-five, so the course isn't really longer than it would have been as a par-72.
I wonder what the players enjoy more, to have two good chances at birdie or par and not to be overwhelmed by not standing a chance to reach the green on a par-four in two (or more strokes depending on their skill level), or the chance to get below a certain gross score irrespective of par.
Strange, this golf.