Here's some examples of why a Default Might be A Great Thing for your Tax Case,
1. By owing more taxes (2014 and 2015 for example), the new taxes could make you now qualify for an Offer in Compromise. Previously your lower balance of taxes due, $15,000, for example, disqualified you from an OIC. Now that you owe $40,000 you might hit a new threshold.
2. Perhaps the fact you couldn't afford your monthly payments is an indicator that you are now an Offer in Compromise or Currently Not Collectible candidate.
3. Finally in 2016 - people are often defaulting their agreements due to non-payment for 2014 taxes. But that doesn't even factor in that you might owe taxes for 2015! A "re-think" of your case might have the triple whammy of addressing your old taxes, 2014 taxes and 2015 taxes as well. That's pretty sweet.
4. Defaults offer advantages in timing as well. We usually have several weeks to sort out our options without the consequences of levies.