> As technical folks, it's our job to learn how to say "no", and not just in an abrasive way that shuts down the conversation, but to work with project managers and decision makers, understand the reasons for their decisions, and push back firmly but using language that they can relate to and speaking to their problems.

That gets back to company culture (which others have identified higher up). Not every organisation responds appropriately when developers push back (either due to imposed deadlines or office politics).