The more experienced DM's and such have gotten past the "honeymoon phase". We all thought, before becoming a DM, that it would be fun and easy and lots of free diving. A good DM makes it look fun and easy... and we bought it. The reality is that the job is more difficult. The responsibility is great. I typically average 4 real life rescues per year. I have a friend, that is definitely one of the best (MSDT, over 4000 hours at sea, captains license, over 2000 students), had 4 deaths in one year. None of them were possible recoveries. In fact, all of them were health related issues. So... death is a real possibility. Don't get me wrong... the majority of the trips are pleasant. And some are just outstanding. But you always have to be ready and vigilant, this over time does wear on you.
Now DM does not automatically mean you are good at it. It's a natural thing, or learned through lots of experience. I know of some Instructors that are terrible DM's, but great instructors. So it's more "what you make it". I hope this doesn't discourage you, it certainly isn't meant to do so. I'm a charter owner, and this is my experience. This statement is directed at those that want to DM for resorts or charters.
There are as many reasons and directions for DM as there are ways to get there...