One thing I don't believe has been noted, yet: We Yanks truly fear the prospect of Med-mooring... :-)
I'm not going to admit to fearing it. To be a competent skipper, one needs to be able to play the hand they're dealt at any marina. However, one has to admit, this is the least desirable. It's not simply the more complicated approach, its the propensity for damage. Sure, you may have to slip between a couple of boats, but what about the next guy having to slip in next to you? Constant worry. Then, boarding from the transom isn't always straightforward on all ships and makeshift planking, if necessary, can chafe.
......... American sailors can be surprisingly resistant to the notion of rafting up......
This one marks me to a tee. After dropping a bunch on a topside paint job, no one is going to ruin it but me!
Further, I get a little particular on how my decks are treated, what you walk on, what you can pull on, etc. I've seen too many others treat their boats as disposable and it would make me nauseous to have other climbing across.
As far as personal space goes, it depends on the day for me. Some days I want to make friends, others I want peace and quiet. Both need to be available for me to consider it good cruising grounds.