It just isn’t.
With the latest hostage crisis possibly brewing, that point cannot be made enough. Raising the debt ceiling does not authorize new spending, only authorizing new spending does that. Raising the debt ceiling just authorizes payment.
Look at it like this: John Boehner, Mitch Mcconnell, and Harry Reid walk into a bar (so many ways this could go!). They decide to run up a big bar tab, lots of bourbon. At the end of the night, the bar tender wants to close out their tab. But they bought too much bourbon, and will have to put the tab on their credit card, so they do. When the credit bill comes at the end of the month, they choose not to pay it.
In our (admittedly imperfect) analogy, the bar tab is the federal budget. The bourbon can be cruise missiles. Deciding not to pay the credit bill is not increasing the debt ceiling. Failure to raise the ceiling is not fiscally responsible, its a vote not to pay the bills. Now we can argue over how much bourbon we should be buying, but once we drink it, we have to pay for it, regardless.
It is just not responsible to fail to pay our bills. Again, we can debate whether or not we should run up these bills in the first place, but paying them is not optional.
520 Chestnut 
I’m not entirely sure I agree. When the three guys in question run up a credit card bill, they amass debt. Paying off the credit card bill isn’t adding to the debt, it’s reducing it. This is what the debt ceiling is supposed to force them to do. To correct your analogy, I would argue that the debt ceiling is like a credit limit. The credit card company says they only trust those guys with so much debt before they need to start paying it off.
I think the argument surrounding the debt ceiling is ridiculous and serves as an excellent example of how congress’s whole spending paradigm is out of whack. Speaking so generally as to border on stereotype, the right wants to spend tons of money on cruise missiles, border patrol, etc. while the left wants to spend money on student loan programs, economic stimulus, other social programs and, in the case of Obama, expensive drone wars. The two sides then come together and make “compromises.” You give me some of mine if I give you some of yours. If it benefits someone in congress, then someone is going to advocate for it. The debt ceiling is the right’s way of sticking it to the left. “I think we should stop incurring more debt. We need to get ourselves under control. Unfortunately we’ve already bought our cruise missiles and we can’t end the war in Afghanistan now, so you’re social programs and stimulus are going to have to go.” On the flip side, this gets the left talking about how the right spends too much money (even though they usually get behind it) and/or how debt never was and never will be an issue.
Personally, I don’t like the idea that congress spends with reckless abandon (and given how they make decisions, I do mean reckless). I’m not saying end all defense spending or end social programs, but there needs to be something in place that forces them to make choices. Arguably, the debt ceiling could provide such restraint. The problem there is that we have gotten so used to just raising it when we get to it that it’s meaningless. What’s worse, arguments made to not raise it are motivated by animosity between the parties, not fiscal responsibility. My opinion is that congress should have a serious discussion about the debt ceiling during which they pick one of two options. 1. They raise the debt ceiling but pass a bill saying they will never raise it again (save for very, very specific emergencies), or 2. They eliminate it all together. The first option will force congress to get their spending in line and their affairs in order without screwing everyone now (though it’s highly likely that they would mess that up and we would end up right back here again in however many years) and the second option acknowledges that congress actually has no interest in controlling their spending.