Yes...I also think lack of communication and misaligned expections between server and guest can be the root of the perception of poor service. Maybe there are some who hear about others' experiences with their serving team and feel let down because they didn't get the same "treatment" as someone else, for example magic tricks, special dessert. And sometimes mediocre service is just mediocre service, no excuses.
We had had "expectations" issues on our last cruise. For 4 straight cruises we had the same Head Server on the Wonder. We were used to really great service and all of the little personal touches that come with having a Head Server who has known you for years.
We didn't cope well with our transition to the Magic

The first night at dinner felt very strange, the servers were pleasant and efficient; however that "welcome back, so happy you're here" feeling was missing (obviously). We barely saw our Head Server that night (barely, like in passing on our way out the door). We definitely weren't excited about our serving team
As luck would have it, we were "randomly surveyed" the next morning at breakfast about our dining experience the previous evening. We gave honest feedback (positives included).
Fast forward to dinner...Our serving team came and talked to us about the survey. It was a pleasant, positive conversation. Our server said she was grateful we took the time to share our feedback, and she was sincere. The team worked very, very hard that evening to make things right. At the end of dinner, the Head Server delivered a special treat. She had to have taken the time to get in touch with our fave Head Server on the Wonder to know about this one. Definitely an above an beyond moment. They turned out to be a spectacular team, enough so that we canceled our Palo reservation so as not to miss an evening with them. A great cruise and a happy ending. Glad we spoke up.