"Uncle Bob" doesn't provide any really provide proof for his argument any more than Jeff & Joel did. He says "The vast majority of the code I write, I write test first. (And no, Joel, this isn’t a waste of my time.)"

But how do you measure wasted time. Or conversely, how do you measure success?

Jeff and Joel have in the past measured success by user base size and profit. "Uncle Bob" doesn't define success or good use of time.