Part of the reason why it was easy was because I knew that if I put in the effort, I would almost certainly pass the course. At uni, if you're smart, the odds are always stacked firmly in your favor.
Failing a PhD thesis during the defence is apparently a 'rare occurrence' in most universities.
By contrast, the odds of your startup not failing are like 10%. Now if we're talking about actual 'success' then that's like 1% or less (it certainly feels like that from where I'm standing).
With these sorts of odds, you don't have this feeling of 'meritocracy' that you might get if you came right out of uni.