Occam's Razor (to over simplify) stands for the proposition that the most basic possible explanation is likely the correct explanation.
The simplest explanation to explain the behavior of Cantor et al is that his goal is to humiliate Obama by refusing to make any concessions on the assumption that on the deadline, Obama will cave in to his demands rather than risk a default. When Obama caves he can claim victory, rub Obama's nose in it publicly and become a folk hero to the lunatic fringe that controls the GOP. Obama will be the one to sign off on major Medicare and Social Security cuts, etc. Cantor could not care less about good public policy or even reducing the Federal deficient (In 8 years of Bush when was a balanced budget ever submitted?).
This is zero sum politics and Cantor believes that all he needs to do is refuse any and all compromises and Obama and the Democrats will have no choice but to cave to his demands.
And Cantor may be right.