Just like a restaurant or movie review, I always take these lists with a grain of salt, especially something as subjective as selecting a "best" cruise line or a "best" ship. Sure, I may or may not read these reviews and lists but the only review or list that matters to me is my own and what I think is the "best" to me.
If my favorite ship or line isn't mentioned, my feelings won't be hurt, and I certainly wouldn't stop cruising that line because it didn't make some list or someone online had a bad experience.
For every person that wouldn't take these list seriously, there will be someone that does. They might not be sure what ship or line to go on, or maybe they are on the fence between 3 of them. They find these lists and decide to go on the one that got the highest rating.