Believing in the work the author was/is doing is one thing, but I can't help but wonder if/how they still believe in their boss.
It's pretty easy to forgive mistakes if you believe people made them for the right reasons, and especially if those reasons are important and the consequences of the mistake fairly diffuse, as might be the case here. Also, given Zeldman's prior work he clearly believes in the power of big ideas; he's surely more likely than most to see the need for pain now to prevent much more later on.
Doesn't mean we have to agree with him; just that it's not hard to empathize with it.