I should perhaps have said more clearly that I was talking generally about the view that "the behaviour of the businesses I give my money to isn't my problem" (paraphrased, not quoting any poster), not specifically about KU.
The only thing I know about the business side of KU is Scalzi's blog post. Based on that, "unethical" may be too strong a word. But it looks like it's bad for many authors because of the "sharing a fixed pool of money" model, and bad for readers because it encourages authors to split up books into lots of small parts, which makes for more annoying reading.
I avoid Amazon as much as possible because I don't think it's in my interest that any single actor in the book market is as powerful as Amazon is, and also because I've read some horrifying stuff about working conditions for Amazon's employees.
"too strong a word" looks clumsy. Is "a too strong word" better? Any suggestions for saying that in a better way?