It took me 10 years to learn to shut up at corporate meetings.
Higher management does not want to hear why their ideas won't work. Even when confronted with reality, they will quickly forget that you WERE CORRECT. You only will be remembered for being argumentative, for rocking the boat, and when layoffs come you will be first, or when promotions come you will be last.
When upper management comes up with an idea, however stupid, ALWAYS EMBRACE it. Remember -- they spent a bunch of time coming up with this idea, so it MUST be great?!? Corporate ideas are subject to the effects of evolution, good ideas thrive and survive, bad ideas quickly go extinct.
No one will remember the ideas that go extinct, they are quickly forgotten. But they will remember that you were (or were not) a "team player". (Whatever that means.)
If you are always positive and never point out management's inadequacies, you will promote faster, earn more money, and retire earlier.