I really didn't enjoy reading this article, not because it wasn't well-written but because I feel like you're putting the responsibility for your discomfort on the wrong group of people.
On the one hand, I totally understand your frustration, and it's perfectly valid. On the other, I don't think there's anything wrong with people making use of whatever facilities they need or prefer; and as at least one commenter has pointed out, there's usually plenty of coffee shop infrastructure for everyone so the "I got here first" attitude isn't as tragic as you make out.
I think the real issue here is that we should all have access to free shared public workspaces with basic amenities and wifi and desks and windows. For those commenters who have excellent libraries in their areas, that's a fantastic solution, but these days I don't think most people have those close by.
We need to hold our governments and municipalities accountable for making sure that all their citizens' needs are met!