Well, first of all, I'm sorry that this has happened to you, but as you say, when the trip isn't economical to run, no one wants to lose money. It isn't just about you, but it's about staying in business during hard economic times (or times of year) and continuing to support the entire dive community, not just one guy or family.
That reeks of "doesn't know how to run a business."
Dad owned a car dealership for 30 years.
You do realize that the dealership doesn't make money on EVERY car they sell, right? Sometimes they sell a car for what it cost them to get it on the lot, or even eat a loss because it's just good business. I'd sell a car for what I paid for it if it meant I could keep a customer from going to the guy down the road. Because I know I'll get his business next time and I know I'll get his business in the service department. The idea is to sell more cars at a high profit so that when you have to give one away below cost, you still make money over the spread.
A card counter in Vegas doesn't win every hand but he still walks out of the casino with more money than he walked in with.
That was a hard thing for me to comprehend as a kid and when I got old enough to have an opinion I'd run around the dealership trying to be in charge, and didn't know jack, and didn't know I didn't know jack, but I was the boss's son so I thought my opinion mattered. I'd bitch because dad was "losing us money" by selling a car for $17,000 when we paid $16,000 for it. His words were, "Son, you don't get to eat steak & Lobster on every deal." That guy that drove off our lot with our thousand bucks and a new car would be paying our service guy $165 per hour for the next 3 years. And when he got ready to buy his next new car, he'd come right to us because he thought he "got us" the last time.
Same way with this "fuel surcharge" some boats have. If you're profit margin is so low that it's gonna bankrupt your business if you to pay 10 cents more per gallon for your fuel without pushing that cost off on the customer, then you need to go to business management courses at the community college. That's about as tacky as charging a 10% "air conditioning surcharge" if you have to run the air condition in the shop during the summer.
I can feel the dudes frustration. But lucky for me I live at the beach and have the luxury of just calling the shop and saying, "Hey what you got going out tomorrow". I'd be pretty pissed if I drove 6 hours and showed up with all my gear and the shop monkey told me the trip was canceled. I basically quit signing up for charters after three of them got canceled for "not enough on the boat". That was frustrating enough living 10 miles from the shop because It screwed up my plans for the whole day.
I realized I have the advantage living right here at the beach a couple years ago. If they have a ride that's 1 or 2 short of making a full boat they kept begging me to go on the charter since I'm in the shop every day. One day, when they begged me to go on a charter that was 1 short of a load, I jokingly said, "Well, since I'm the one that's gonna determine if you have to refund all that money and cancel the trip and have 6 pissed off customers, I ought to get a 15% discount." The shop owner actually agreed. So now I check with them often during the summer to see if I can offer my "services".
I know there's expense to running a boat. That's called the cost of doing business. There's days that the service dept guys just sit around drinking coffee because there's nothing to do and customers just don't need a service dept. that day. But we don't turn off the OPEN sign and go home, we still pay the service guy and the service manager for 10 hours of work that day to be available in case a customer does happen to come in. Because the OPEN sign days 7am - 5pm. Just like a canceled trip, if the guy wants his oil changed and he drives up and the sign says 7am - 5 pm and we're closed because we lost money TODAY he's gonna go somewhere else to get his oil changed, or go somewhere else to dive. That means we not only lost his business today, but probably the other 10 times he wants his oil changed.
The business management part of it is that we'll make enough money the other 5 days to cover that day when it rained and everyone was sitting around playing cards in the break room and we made nothing today.