I should start by saying that I am not unsympathetic to your lament. That said, and in the spirit of a good discussion, I do have a few comments based on my personal views and experience.
First the conservationist have a go by getting rid of copper in antifoul, then sulphur in fuel followed by protecting so many anchorages in the guise of conserving grass or the lesser know pink spotted sea horse.
Then there are holding tank regulations.
I would imagine that round the world the effluent floating out to sea and the emission from factories coming down as rain are far more harmful.?
You're right....how lawmakers in some states can go after weekend sailors who pump a few gallons overboard and ignore municipalities that dump tons of sewage is beyond me....but maybe they start at the point of least resistance and move on up the sewage chain from there.
Re the sea grass...in many places where sea grass is an issue (and here I'm thinking of primarily of the Caribbean where charter boats seem to be everywhere), local governments or local entrepreneurs have put in mooring fields to "save the turtles". Some times the purpose of the rules restricted anchorage are designed to put money in the pockets of local mooring operators, but in others it is a genuine effort to help out turtle and conch populations that depend on sea grass beds for forage. For example: on the east end of St. Thomas the local government has installed moorings at Christmas Cove. The moorings are free. I've snorkeled through most of that mooring field and can testify that dragging anchors play havoc with the sea grass beds. They don't call them "plow" anchors for nothing.
Where the density of boaters is high the impact of marine heads and anchors is a bigger problem than you might think.
Countries such as Greece then throw in another tax specifically against boaters.
Ask Willy Sutton why people rob banks? Same applies here. Europeans who have expensive yachts they keep in Greece are seen as a source of income by local politicians -- and an income that doesn't ask their constituents to pay the tax.
Chandlers seem to think of a price and then double it and add 12.
This is partly due to the economics of serving a relatively small market for boating products coupled with the relatively specialized nature of "marine grade" products, and partly because of the general view of the relative wealth of yacht owners. (You know the saying: If you have to ask how much it costs, you can't afford it). It's also a function of the mentality of boaters who after spending tens, if not hundreds, of thousands on the boat are less likely to sweat the small stuff. Boys shouldn't complain about the cost of their toys.
Is it that the leisure boating industry is an easy touch and they know we will accept all these things or are they right.
I presume you're speaking here of the rule makers. In some things they're probably right -- in others they're shameless, overreaching hypocrites.
Should we do more to protect grass and sea life....
...and accept the high prices and taxes for what we enjoy doing
That's up for each of us to decide, isn't it?