I think to me it's the math thing and the unknown future. What if the program fails in year 9 and you've only paid 27,000 of your 165,000 debt. What is the percentage of your $250 going towards principal and interest? What if you lose your current job, will a new job qualify or does it start over? Your "black hole" could be a savings account or investments in mutual funds. Then at the end of the 10 years and if all the stars aligned and you actually still qualify for the loan forgiveness that "black hole" fund could be a good kick-ass year spent traveling/living overseas. That would be a cool reward.
I'm not passing judgement or anything. I'd travel if I could (I'm working on some debt payoff myself) but no big trips till I'm done.