Neither side is overtly threatening a default.  They're both saying "we all want to avoid this, but if it happens, its the other side's fault, because the other side wouldn't make a deal."

The fact is, Congress has to agree to raise the debt ceiling for the federal government to continue borrowing money.  Both parties understand this.  Both sides know unequivocally that no matter what legislation they pass, eventually they must reach a compromise regarding spending if they are going to fund anything.

Based on that, I don't think it can accurately be said that either side "did its job" until a compromise is reached.  

After that happens, if you think the deal they made was a bad one, its perfectly fair to criticize whichever side you think forced a particular cut or spending measure that you feel is bad for the country, and its fair to criticize your own party if you think they failed to represent you during the negotiations.  Escaping political consequences of the latter criticism is exactly why the theatricality is part of this messy process.

Its been a little bit weird watching it this year because everyone in the media is acting like this has never happened before.