I have a lot of problems with this story, and with your arguments in favor of it.
> the talent market in Silicon Valley is so hot right now,
> the only folks staying at Yahoo are the ones who have
> stopped caring
I
guarantee you that there are people working at Yahoo! solving difficult and interesting problems, which many of us would envy. Not only that, but there are also going to be people working there now who value stability and have a sense of loyalty to the company they work for. Not everyone is going to jump ship for the new hotness every 3 years, and software engineering is not a monoculture where we all share the same values. I think it's incredibly problematic to broadly assert that anyone working at a given company is not worthy of employing.
> 3. Yes the article / his announcement is sensational. But look at the
> general idea: expecting engineers to refuse support to business doing
> immoral things is taught in every university ethics class. Why not include
> ethics questions in the interview?
So Yammer should only allow a single interpretation of ethics? What about someone who doesn't believe this move is unethical? Yahoo is after all a business, and according to some, the ethical way for a business to behave is to maximize shareholder value [I do not agree with this, for the record, but some people have definitely said it here and elsewhere.] Apparently Yahoo believes this move will achieve that goal. [Remember, we're looking at ethics here, not whether this is a good business move.]
Additionally, if one can make a good case for his/her stance on this issue, does that mean that he/she will be considered as an exception to the no-hire rule? If the CEO of Yammer wants employees who will correct him on ethics issues, then certainly having strong critical thinking skills, and ability to present a compelling argument for an issue should be far more important than being able to "Patents are bad, mmkay?" And having a diversity of viewpoints on these issues would surely also be a benefit, would it not?