Since the Federal government accounts on a cash basis, Roth conversions generate tax revenue "now," making the budget situation look better, and Roth contributions likewise generate more current tax than traditional IRA contributions. Same for 401(k)'s.
I don't want to wander too deep into comments that could be construed as partisan politcal, given the nature of this group. But I will say that Roth contributions and conversions amount to another form of "borrowing from the future" in terms of the U.S. government's fiscal situation. That much seems indisputable.