It is not black and white, both morally and in terms of the way I work.
Let's say that certain choices, strongly supported by my boss, who is ultimately responsible for my career in the short term (and the short term career consequences of my actions then inform my career even further down the line), are seen by me as not particularly brilliant, maybe even "dumb." If I say nothing and nothing happens, the product we are developing may not work as well as it could, perhaps the company's revenue will drop by a 50th of a percent. But should I risk my career to tell my boss that their ideas are not brilliant?
Years ago, when I was younger and more idealistic, I would have expressed my opinion on the choices made, even forcefully so. After I got fired at one of my previous jobs, I tend to side with the boss, strategically.
And before anyone, legitimately, thinks I am a coward or a "bloodsucker," let me make it clear that I was not the one who put my boss in the position they are in, the company is not mine, and the company can fire me tomorrow for any reason, even for no reason. Then, maybe at some point it will be too much to handle and I will decide to leave, but as I wrote, it is not black and white.