People have come before us, failed, learned, written it down. Scientists have figured out what works, and proven it. Economists have gained significant understanding about the long-term impacts of short-term decisions. And historians have seen it all before.
How dare we, then, decide to just wing it? To skip class. To make up history. To imagine that science is a matter of opinion, something optional, a diversion for the leisure classes… How can we work in the marketing tech field, for example, without knowing about David Ogilvy and Lester Wunderman and Claude Hopkins? Or Kaushik and Shirky?
If you're doing important work (and I'm hoping you are), then you owe it to your audience or your customers or your co-workers to learn everything you can. Feel free to ignore what you learn, but at least learn it.