I have worked with designers, including entrepreneurs, for over a decade and completely support Irene's POV - designers are like anyone else and don't want to work for free.
I think there is something else in play here - the point that designers won't work for free (equity) is not the same as no design entrepreneurs (someone who starts a new business, creates a business model, etc..)
Having worked in design in large corporations, startups, and taught at design school - a real issue is what was mentioned to in the article but I will state more explicitly - Design schools are inadequately preparing designers for the business world today. Many design schools are still operating, as one program head told me "the companies hire our students because they can sketch ideas really fast and really good."
There is a mindset that can be "activated" in young designers. Yes they have pride in their craft, yes they are learning their discipline first - but they can learn what it means to put that discipline in context of doing good making profit. Those designers that are exposed to this get it very quickly.
And in fact they can be more open to the idea of fast failure that is necessary for breakthrough innovation. That is one area where the basic design discipline teaches them well - "Give me two hundred sketches by tomorrow that solve this problem."
They get used to coming up with a lot and feel fine to throw it away.
What would help would be taking that energy and giving it greater business context, greater sense of ownership for outcomes versus "decoration station" - and you have an entrepreneur who just happens to be trained in design.