Well, they have been around since Carnoustie 16 was built so they must have some merit.
My former college golfer son and I were discussing this on this very day, (he woke up and saw a preliminary routing on my screen, and noticed 2, 250 yard par 3 holes....one was really just a copy and paste centerline that was going to get shortened anyway) so we discussed it a bit.
Right after the Oakmont open, I was inspired to design a 285 yard par 3 from the tips. It has not gotten rave reviews. I have previously built par 3's of about 270 yards on a few occaisions.
I like the general concept of using par 3's to force back tee players to use a long iron to reach a green in reg figures (as opposed to reaching a par 5 in 2) It seems that when you get that long, most good players say its okay, but want the length to correspond right to THEIR 3, 4, or 5 wood, rather than having them hit a soft driver, etc. I guess it is a bit more palatable to "invent" an in between shot with shorter clubs......
Perhaps oddly, better players I have talked to prefer the long par 3 into the wind, so they can hit it hard and have the wind help it settle. Downwind, they feel they really have to butter cut the shot and hit it high to get it to hold. The long and short of is that players don't mind a par 3 up to 240-250 but I have found little favor in designing par 3 holes that require a driver. Not that I thought I would necessarily, but even 270 is a 3 wood for a few, but you can't necessarily design for them.