As a catholic, I am well aware about the error, sins, and mistakes done by the catholic church. And I am not going to justify any of all those mistakes by pointing out the mistakes done by people of other religion.
On the other hand, accepting the wrongdoings of the church does not make me agree with the wrongdoings done by people of other religion either.
Many things about catholic church which I don't agree or proud of, but I am still loyal to my church. Or maybe I am loyal precisely because of all those weaknesses?
I think we should clarify the meaning of "Catholic Church". Is it sufficient to describe the wholeness of the church just by looking at "a bunch of old people in vatican"?
Of course we can view the church as an "organization" (although the word "organization" is somehow inappropriate in my opinion). But the dynamics and diversity of ideas within the church can never be represented by merely a handful of person(s) who happen to be the leader(s) of the church.
Just by looking at writings or lifestories of Teilhard de Chardin, Hans Kung, de Mello, R. Panikkar, and many more, you will see the diversity inside the church. These people are loyal members of the church, but with such a different or often opposing ideas to the formal disposition of the pope.
I am just a layman, like hundreds of millions other catholics around the world. But even among the laymen, there are many different views also. Many of us go to the church every Sunday, attending the mass, and listen to the sermon. But that probably is the only contact we have with the catholics authority. The rest of our daily life are shaped by our own spiritual view, which might be different from the content of the sermon we hear each and every Sunday.
And that, my friend, constitutes the real and significant part of what you call "Catholic Church". And that also describe an important difference between today's church and the church of middle ages where the church authority had a very influential power over the daily life of the people, over the state, the politics, science, etc. Today, that power has been reduced to a very minimum, or probably to almost zero.