It is not about chocolates, towel animals, or midnight buffets, per se; it is about the overall experience. The devil is in the details. In my experience, a cruise used to feel special. Food was excellent, service was outstanding, the little things add a lot and it was money well spent.
Once you start stripping off the toppings, well, sometimes the base product is not enough.
It is a lot like food dishes. You start removing the "extras" and it just doesn't taste the same or have the same enjoyment factor. Yes, it still provides nourishment, but it no longer holds the same appeal.