Well, the article makes some strong and accurate criticisms of Donahue. I don’t know if they rise to the level of requiring him to resign, however.
I don’t know why folks are discussing the article author.
You complain about ad hominem, but understanding the author is part of understanding the article. He has a bias born of his anticatholicism. If Westboro Baptist Church issued a statement that Bill Donohue is burning in Hell, would we not be right to consider who was making the statement?
This man that passes for a religious editor on this website calls Donohue,
“a feral child in the playground of the media, spouting nonsense and threats…” Wilhelm shows in this his condescending nose. Then this writer states,
“I say on behalf of reasonable-minded people everywhere…” He speaks for reasonable-minded people about as much as I speak for NASA. If he was reasonable-minded then he would know that he lacks the credentials to write this article. One simply cannot claim to be a spokesperson for a group that one is not actively associated with.
Let us look at other stupid parts of the article:
“Unfortunately one of their (The Holy See’s) most public representatives during this time of difficulty has been a man whose actions are indefensible.” 
I don’t even know what to say about such an ignorant statement. Wilhelm thinks Donohue is a representative of the Holy See???

I guess if Wilhelm represents reasonably minded believers any thing is possible in the world between his ears.
Let us continue:
He consistently speaks for people who have not chosen him and do not finance him, and he does them no justice by presenting his opinions as the consensus view of this nation’s Catholic population. It is for this offense, in addition to the content of his unctuous remarks, that I publicly call for his resignation." Can we all say, pot meet kettle?
While on the topic of hypocricy:
Donohue also suffers from a strong case of hubris.
I do not agree with everything Donohue does, but my goodness, what a ridiculous article from an unqualifed writer. Nothing that Donohue has done makes me think he should resign, even though I am sure anticatholics everywhere would join in the clamor. In any case, it is no one’s business, except those that support this organization and its goals, something which Wilhelm obviously does not.