I don't think Scott would endorse this post today. His attitude now is that most people should commit to donate at least 10%, and then feel okay about doing whatever they like with the rest of their income.
Interesting - my work as a software engineer also feels like "a constant stream of input/people wanting things, while trying to carve out time to work on larger projects + think about strategy."
From what I've read of Cal Newport's blog, the single most impactful change we could make is to reconstruct our pattern of working so that people can focus. Most of his posts discuss that single big idea, but this is one metaphor to get started: On the Dynamo and Email - Study Hacks - Cal Newport.
It's not easy to change these patterns on an individual level, though.