It seems strange to want to eliminate someone else's best employment opportunity simply because it isn't up to your standards.
If you were to take your business to another cruise line that provides workers better working conditions, I could see that, but is not going on cruises entirely really the best way to improve things?
"simply because it isn't up to your standards" is the reason for all labor laws - OSHA, child labor, etc.
We shouldn't treat those born in poverty differently than those born into wealth - and it seems like a tiny step to require cruise ships to treat their workers well.
And neither do they. Their offer of employment is valid for rich people too.
Perhaps they would use the money saved on cruises instead to buy more cheap goods from China and Bangladesh? Those factory workers benefit from demand for their wares, too.
It's a military style mandatory entertainment camp with a lot of retail, and very little space.
They are incredibly deceptive and exist solely to extract money from you (I'm talking about Carnival here)