1) I have not met Hitler but I know him to have been not a nice man
2) I believe Patent Trolling to be evil and therefore those that perpetrate it to also be evil.
Personally I cannot disagree with either statement. Excusing any evil practice as 'a businessman whose tactics you disapprove of and consider to be unethical' is also wrong in my opinion.
The world of business hides too many organisations (and therefore people) guilty of profound immorality. It has become an unfortunate part of our culture that we so often forgive them as 'just business'. Capitalism, as a whole, rarely scrapes above amoral.
The word 'evil' has an ancient meaning that doesn't only include mass murder and it certainly includes extortion.
What? That's exactly what he did.
Also, "One is a businessman whose tactics you disapprove of and consider to be unethical," the other was a politician whose tactics I disapprove of and consider to be unethical. Gotta love euphemisms that turn everything into nothing, and applying them selectively.