Because you are going to see an attempt by Team Obama and its friends in the media to blame the sluggish economy and paltry job growth on the Republican refusal to give Obama a clean debt ceiling increase.
And it already has started, with Paul Krugman claiming the debt deal will slow the economy. So according to Team Obama, you can add the debt deal to the Arab Spring, Japanese Tsunami, the gravitational pull of the moon, and of course, George Bush, as to why Obama is not to blame for anything bad that happens during his administration.
But in announcing the deal, Obama highlighted what for him was a feature and for Republicans a bug, namely that there are almost no cuts in planned spending the first two years (indeed, there never are any cuts, just a slow down of the increase)(emphasis mine):
The first part of this agreement will cut about $1 trillion in spending over the next 10 years — cuts that both parties had agreed to early on in this process. The result would be the lowest level of annual domestic spending since Dwight Eisenhower was President — but at a level that still allows us to make job-creating investments in things like education and research. We also made sure that these cuts wouldn’t happen so abruptly that they’d be a drag on a fragile economy.
Keep this quote handy, we already need it.