My ethical framework allows for disagreements on the nature of what is and isn't ethical. It doesn't matter if you and I agree some behavior is unethical. Some other group of people clearly consider their behavior to be in the realm of ethical given their worldview, location, upbringing, etc. So no amount of us whining about how unethical it is really changes anything, does it? I personally consider massive hoarding of wealth unethical... so... from a total harm standpoint... yeah it's kinda grey.
They outright admit that they see the targets primarily as money bags, and that they are making the economy better in exactly the same way that breaking windows makes the economy better, and your opinion is that it's ethically blurry?