Ryan ignores Social Security because he knows privatization won't fly and he doesn't have the courage to propose a mainstream reform of the system that would be unpopular with conservative mandarins. He exempts seniors and baby boomers from his Medicare plan because he doesn't have the courage to take on a powerful Republican voting bloc. He eschews details, basing the bulk of his plan on little more than theoretical spending caps, because he doesn't have the courage to explain what his spending reductions would actually mean. He focuses most of his cuts on programs for the poor because he doesn't have the courage to tackle weak claims rather than weak claimants. He gives the Pentagon a pass because he doesn't have the courage to stand up to hawks in his own party. And above all else, he refuses to consider tax increases of any kind because he doesn't have the courage to take on Grover Norquist and tell his own caucus what every genuinely serious analyst already knows: the only way to tackle the long-term deficit is with both tax hikes and spending cuts.
So explain to me: what's courageous about a Republican congressman proposing spending cuts for the poor, entitlement cuts only in the far future, tax cuts for the rich today, and hands off the Pentagon forever? Nothing I can think of.
I also love the way this is all being framed as "necessary" to save us from the horrible budget crisis we're facing. The Right has had a major hard-on for doing something like this for as long as the Right has existed in its current form in this country. Hiding their real motives behind budgetary excuses? Yeah, that's pretty "courageous", too. And "serious".