It's basically rather easy to re-structure yourself to reduce your tax overheads within Thailand, if you own a vehicle(s) or property that's your main costs, then everything else can be structured or reduced onshore by changing somethings.
For example we bough the land behind us late last year just after they announced these changes to grow fruit and veg, chickens (eggs) etc which reduces another massive on-going cost.
As i understand that saves us 450 THB a day for the household food costs (excluding meat/fish). = 164,250 on average per year, at a cost of 1,000,000 THB within 6yrs (slightly over) the 1,000,000 THB sunk costs then become paid off. at the same time due to the cost(s) of living and factoring the tax bracket 35% we'd have been hit by (again savings) - the tax on that 450 x 365 = 165,000 roughly = 57,750 in taxes.
We are pretty much entirely green (water, power, heating/cooling) so I imagine collectively on-shore we'd be spending roughly 120,000 THB a month going forward - which should be tax free due to the deductions (children, parents, etc).
So they've lost 'income tax' (technically savings) for the wife.
They've lost VAT (by offshoring)
They've lost local community fund flow (spending money into the community).
So their little jaunt has probably cost them 1.5-2m THB in direct-indirect taxes in our household.
X That across the country (i know many people in the HNW doing the same) and it will be a nasty shock for them.