I think this is just another example of a situation where you have to judge political movements by what they do and not what they say. Progressives generally care a little about the deficit, though they’re happy to put it aside to advance other goals. Conservatives, by contrast, appear to have no concern whatsoever about either the budget deficit or the extent of government spending. Instead they’re extremely focused on minimizing federal revenue—they don’t want to close distortionary loopholes, they don’t want deficit-reducing grand bargains—and decades into the movement’s lifespan, it’s time to stop being surprised.
I guess "surprise" isn't the most precise term here. I did write a whole book about how supply-siders took control of the Republican Party. Still, it seems to me that most members of the conservative movement really do want to shrink the size of government. But they have managed to convince themselves that focusing monomaniacally on lower tax rates for the rich is the best approach to achieve this goal, despite overwhelming evidence to the contrary. Now, the motivation here is mixed. You have some true believers in the supply-side faith, and those true believers are well placed at key right-wing publications and think tanks. You have some rich people who benefit from these policies and are eager to fund politicians and policy entrepreneurs who promote them. You have other people who believe that tax cuts will starve the beast, despite copious evidence to the contrary. And then you have a much larger group of conservatives who understand they don't really have enough expertise to scrutinize these claims, so they take their cues from Rush Limbaugh or the Weekly Standard.
There certainly are people who feel satisfied with the results of the GOP's taxes uber alles approach -- people who may not like huge deficits but are mostly gratified to have saved millions on their taxes. But huge numbers of conservatives are massively dissatisfied with the results. I think they legitimately do not understand that demanding huge specific tax cuts and unspecified spending cuts, while anathematizing any deficit-reducing deal with Democrats, is going to produce the exact same results they find so dissatisfying. You can understand what causes a woman to stay married to an abusive husband, but still feel surprised at some level every time she sticks around through an abusive episode.