Look... the process can't be, "Hey you get all the time in the world to build undefined requirements with out providing any sort of insight." The reason you let people who don't code in to the meetings is because they pay your salary -- right? So translate. Give them something that makes them feel you are spending their money correctly.
It's not all that hard to just define requirements, put a line in the sand for what you think you can get done in a two week block, and show your progress on a board -- is it? This article seems to take the stance, "Devs are the only ones who matter and everyone else is someone who is going to make me sit in a meeting I don't want to be in." It's really immature to think this way, and short sighted.
You need some sort of process, some sort of roadmap, so your sales and marketing team can drum up interest for the product and the team can be successful growing the business. This isn't an academic exercise, it's a job, and you work on a team that requires communication to operate.