Yes, it does seem unethical. IIRC these techniques were discussed at length in HN in the 'early days' of the tech startup 'boom' (or at least the early days of HN).
When I click on a button that says effectively "Purchase" or "Buy Now" and I instead get a page that says "Sign up to stay informed" the page has lied to me.
I fully understand that the design pattern solves a difficult problem that we all have: how to know if someone would really be willing to buy your product. Because if you ask, many people will say they would buy it, but when it comes time to pull out their credit card they don't do it.
But it's still tricking the customer into doing something he or she wouldn't ordinarily do if they had known what the button really did.
I understand its not exactly fun to be at the receiving end of that treatment but i fail to see what values it is really violating