Touchy subject or not - my hat is in with kneaf

A business owner is NOT entitled to anything, other than possibly "pride of ownership" and, possibly, "satisfaction on/of success" Tipping the guy that sets the rates for service ? Perhaps in kind (meals, drinks, other), but certainly not in cash. If he needs more cash - up the price, then I'll decide if it is worth it to me.
Arguably - telling you the 15% is expected - is the same - psychologically it is not

The business owner is "encouraged" to make a profit...
and is definitely entitled to keep the profit he makes
But certainly not "entitled" to one.

As for the staff that help make your charter a blast...
I have no idea, but expect they earn a salary short of great. So tips help make their day. week and month
If you can tip the staff $2000 for the week - good for you and good for them - They won't refuse
Instead of earning $500 +room/board for the week - they now split the extra $2000
But it's all about perspective