Andrew,
The short par 3 requires only accuracy.
The long par 3 requires both accuracy and length.
The great majority of golfers have the ability to reach a short par 3.
The great majority of golfers do not have the ability to reach a long par 3.
And, the great majority of golfers do not possess the ability to combine length with accuracy.
Therefore, the demand on their game, as presented by a long par 3, is beyond their ability, ergo, no fun.
P.S.
Anyone who views this issue in the context of the PGA Tour Pro's game is a moron.