My reasoning is that I want Jeb, Christie, Carly, Kasich, and Rubio in the race long enough so that the establishment vote doesn't consolidate under any one candidate.
I despise Jeb and the whole Bush clan too, but I'm not sure that a Rubio or Christie Presidency would be much better than a President Jeb. So let them all stay in the race until the bitter end so the Party Hack vote gets split among them while an anti-establishment candidate rises to the top. The RNC won't even be able to play the brokered convention card if Trump or Cruz get a majority.
It's important to humiliate Jeb, to send a message to those who planned to buy the nomination for him....don't waste your money. Just as it was important that Cantor lose that primary to a better man, it sends the "mad as hell" message. One reason is Terri Schiavo....Jeb is unacceptable and the elitists don't care. Let them go down ASAP!