Any cruise, anywhere should be considered a luxury even by American standards, and so it's a little awkward to sound spoiled by complaining. But you're reading these reviews for the truth, right?
Yes, the Liberty is a beautiful ship, yes, the destinations are jewels, and yes, the initial price you pay to cruise is very reasonable, the good reviews you read are mostly true. A good time can be had and most people will have a good time. We've cruised about 70 days on prior cruises, and my relatively positive reviews can be found elsewhere.
Here on the Liberty, however, Royal Caribbean crossed the line of integrity, fairness, and honesty so many times it became a central (and very annoying) theme to our cruise: "What will they do next to try and dig an extra fee out of our pockets?" They are now treating their guests like targets to hawk and up-sell to 100% of the time.