I share your concern and applaud your bringing it to wider attention. May others follow your lead.
I think training institutions can certainly play a part in bringing some common sense and good seamanship into the use of dinghies. That said, I do not think it is the whole story or even most of the answer. Most everyone goes to some form of driver’s education, but there are still lots of drivers who take risks with other people’s lives as well as with their own.
It is a bit of a theme I have going that we, the recreational boating community, are best served by monitoring, even policing, ourselves. In your shoes, I have actively motioned for those going fast in anchorages to slow down with open hands pushing down. If possible, I speak to them. It is often dinghies, but small runabouts run similarly fast and they throw up a big wake.
A group that may be useful is the Seven Seas Cruising Association (similar to the UK’s Cruising Association) as there are often a number of SSCA boats in any Carib anchorage and they are likely to share your concern: Their motto is “to leave a clean wake”. (Get to know their burgee.) They might be a good group to join as well as we benefitted from membership in CA when in the UK. Boats with children are also likely to share your concerns. Gather some forces and make yourself heard: possible also speaking up on the morning net.
Good luck with it and let us know if you get anywhere.
My best, Dick Stevenson, s/v Alchemy