Like BooMan says...exactly when was The New Republic some sort of venerable institution? Not in my lifetime.
To the extent that good people are losing their jobs (though everyone seems to ignore the fact that other than Foer and Wieseltier, they quit) well, I'm sorry about that, and if they fail to find new career possibilities then bummer for them. Though, again, they did quit. Maybe with good reason, but still!
But otherwise we're just left with this idea that we must lament the fact that TNR went from having one truly odious boss that everyone pretended wasn't odious to having a new boss that for whatever reasons (maybe good ones!) many of the current staff don't want to work for. Life sucks sometimes. But, venerable institution? I guess if you just ignore all the bad stuff over the last 40 years.