Stuff and nonsense
Anyone who bangs on about an "80% increase" without saying what it is an increase over deserves to be soundly ignored. And anyway, since when did we start talking of percentages of percentages in this way? It is hard to escape the conclusion they are trying to scare and mislead - as thought the new tax rate was 80% or something crazy instead of the actual 18% (compared with 10% in the best case before).
Frankly, as a small business owner, I'm not much exercised over whether I get to keep 82% or 90% in the unlikely event that it ever becomes worth a lot. On the other hand, I do appreciate it being a simple rule, rather than feeling some kind of nagging doubt whether I should pay the accountant thousands of pounds now to wangle things into a tax efficient structure that only they understand.