A quick count of my new designs shows I use a par 5 about a third of the time. It doesn't really matter to me.
I do care about sequence and speed of play on the opening hole. For that, I think you need a good length hole so that any duffed tee shot gets hit right away, not waiting for the group to clear. Of course, par 5's do this, as do par long par 4's where we leave enough length for a max second of 200, after a dubbed shot of under 100 yards, even from the white tees.
The problem on par 5 holes is you don't want a reachable par 5. Figuring that the 320 yard hitters won't be playing my course very often, we keep them under 600 yards (if just barely, or add a button tee for that 1%) because for the average good player, even 560 is not reachable very often, and keeping it that short and/or further middle tee adjustments, makes it an easier true three shot hole for others.
If its easy or hard, I doubt it would affect many "great courses" attempts. Even the best courses have a few easy holes once in a while.
BTW, I also believe a first hole ought to be visually good, even if easy, and its a bonus if it looks good from the clubhouse, where golfers get to see it not only playing, but in the restaurant, etc. One of my favorite first holes is a gentle dogleg right, with a series of target bunkers facing on the outside/left side of the fw - visually good, and not likely to snare many golfers on the first hole.