I'll never understand why FT always cheers for Goliath. Why do so many people support multi-million $ companies when they mislead customers?

The problem for this hotel is that "All Inclusive" has a commonly understood definition in this industry. That does carry weight. If they offered "all inclusive" (as commonly understood) and you accepted, then a contract/agreement has been formed and they cannot change terms without your consent unless such changes are permitted in the existing agreement.

The problem for OP is that there isn't much you can do to force them to honor "all inclusive" aside from legal action ... and that's probably not worthwhile. To be clear, you have a case whether the detailed description specifies limited "inclusions" or not (just might not be a strong case). This will vary by legal juridsiction.