A mandatory $80 daily DSC, and mandatory 20% on a "make-believe" list price of $110 a day for drinks, is a specific NCL problem. It's not a business practice I want to support.
Your comparisons are not equivalent. Sales tax in the USA, which I'm not fan of, and don't have to worry about here in Oregon, is not included in the price because it is different in every state, and sometimes different in cities within that state. That is very different from a national VAT.
The only place in the USA now where a 15% tip is 'essentially' mandatory is in those few states left where servers make less than minimum wage. Here on the west coast now, everybody earns at least $15 an hour and up and a backlash is starting as many people are starting to get sick of the extortion on every screen they see these days.
The only thing that's really comparable are hotel "resort fees" that often aren't revealed to you until the final click, but legally they still have to be revealed pretty prominently, unlike DSC which you have to read through a myriad of tiny print to discover your vacation is actually going to cost an additional $1000.
So yes in summary, I put the blame on NCL. not the USA.