The co-founder's time is worth what? They just got investors to hand them millions of dollars over a few meetings, on the assumption that if successful, they'll be worth hundreds of millions one day.
You are one of dozens of applicants. Some guys with 20 years have the problem that it was the same year over and over. How do they know your skills are even current and relevant?
If you're an experienced programmer, maybe you're going to make $50 to $100 an hour (depending on your market). But if you're applying to multiple firms, wouldn't you put yourself to work at that opportunity cost to differentiate yourself enough to get the job you want?
Why wouldn't you be willing to jump through whatever hoops necessary to get the job you want?