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?
I wrote a post last year, (read it here), that was a bit tongue in cheek about some general complaints people had made to their travel agents.
The below complaints are genuine complaints that I've received, personally, from cruise passengers.

"I got onboard and the wood was fake plastic, not real wood at all. It ruined the effect of the whole cruise. Can I have a full refund please?"

"I had a free upgrade from an inside cabin to an outside cabin but the outside cabin had an obstructed view; who do I complain to?

"The person next to my balcony was smoking, can I have some compensation?"

"I booked a suite cabin but on our table for dinner there were people who had booked inside cabins. Is this normal?"

"The cruise line are making me print my own tickets out, it wasn't like this five years ago!"

As I said, all of these are genuine complaints from people I've personally booked cruises for. Whilst some of the above may sound a bit extreme it always amazes me the things people do complain about.
E-tickets;
luggage labels;
smoking policies onboard, (for and against);
meal sittings, the list goes on and on.

Don't get me wrong here, I'm not moaning about my passengers. Even a quick glance to your right on the Rate My Service section of my blog will show you that I'm happy to bend over backwards to help anyone. It's just some of the the thinks cruisers moan about either sound really trivial or should of been researched before they booked the cruise.

Whilst I try to give as much information to someone as I can before they make a booking and I'll answer all their questions that I can, I can't cover everything.
Do you think people should do some research about the cruise they're doing before they contact a travel agent? I'm always amazed that people moan about cruise line policies that should have been researched before booking; like smoking on balconies; like set dining times; like dress codes, but people quite often book the cruise, pay for it, get onboard and then moan about things that they should of checked first.
What do you think? Should the responsibility be with the travel agent who should cover absolutely everything possible or should cruise passengers accept some responsibility for the cruises they book?

Happy cruising.