I think part of the reason for the hassling is that Ocho Rios / Falmouth only gets visited by 1 or 2 cruise ships per week, unlike other ports, which may have ships in port every day, or every other day. I wasn't crazy about the hassling either at Dunns River Falls.
Mmomom, if you're uncomfortable going on your own in Jamaica, but don't want to do the ship's excursions, then you might look at Shoretrips.com. I did this when I went there a couple years ago. Like the ship's tours, I think they look at vendors, and only book reputable ones, and they haven't had anybody miss the ship that booked one of their tours, that I'm aware of, at least from what I've read.
2007 - Majesty of the Seas
2009 - Enchantment of the Seas
2010 - Freedom of the Seas