Are cruisers too unrealistic?

Cruisers, on the whole, are some of the loveliest customers I've ever booked anything for in my life.
And believe me, coming from an insurance background I'm more than used to being shouted at by irate customers.
So my general opinion of you all is that you're fantastic.
There, my backs covered now and the reason I say that is that I've noticed some peoples expectations of their cruise can be a little on, shall we say, the high side.
It's by no means all cruisers, but by the same token it's not really a small minority either.
Is it something particular to cruise holidays or do you think people are like this for all their holidays?