Re: What stops Americans cruising the world?
I had someone in New Zealand ask me almost the same question back in 1985. I love to travel, experience other cultures, visit historical sights.
I can't speak for most of America, but for many, the Schengen limits are a limiting factor on cruising Europe. 90 days is simply not long enough to see even a small part of Europe. As you said, there is SO much history to see and culinary delights to experience. A trip across the Atlantic for a hurried 90 day stay is not very attractive, when a season could be spent in the Bahamas, then heading up to Canada in hurricane season.