I think that in these dicussions people are reprsesenting the diners as cold hearted people, demmanding good routines and good effects, which is totally wrong, there here to enjoy there meal and have a good timeAND SO SHOULD YOU.
I don't think anyone here has tried to give the impression that people in restaurants are ruthless people who demand the best. In fact, I can't think of one post I've read in this section that remotely gives off that impression.
The thing that a lot of the serious workers in this forum try to show people is the importance of being good at what you do, and being dedicated to the art and to the job. Of course magic should be fun and enjoyable...that goes without saying. But like any art, there is a dedication and zeal that should come with performing. It's fun, yes, but it shouldn't always be "easy" work. Just like painting, sculpting, drawing, sports, or any other endeavour, magic is something you must work at to get good. And in a working situation, you must be constantly aware of many different aspects (beyond the magic you perform) and be working to improve those aspects if you are going to truly succeed and be the best for yourself and for the people you perform with.
In my 6 years of working in restaurants, I've found it to be very enjoyable, but also very trying at the same time. It's fun because I love it, but its also hard because I love it. I'm always learning new things, even learning things when I'd rather be doing magic (like finding ways to communicate better, how to read people better, or working on new self-promotion techniques).
So yes, magic should be fun and easy...because you enjoy it. But it also should be difficult because your dedicated to getting better and doing the best job you can for the spectators and the restaurant which has given you a job. And getting better, no matter how much you love something, isn't always the most fun and easy thing to do. There is no professional in ANY job they love that will tell you that the road there was an easy one. Dedication isn't always easy.
But your advice is good, and I think its just as important to recognize and remember that magic should be FUN.