This is a bit of a logical fallacy: the fact that you are not able (maybe even because of your own limited self) to do good in every possible context it doesn't mean that you shouldn't do good in the contexts whee you can!
I'm pretty sure that many monks individuals did the best they could with what they were given. That is very different from it being true for the whole order of the Benedictine.
At the same time I do believe that the spirit of Christianity, Islam and most other religions is inherently good, positive and inclusive and there are definitely people that use that as a guide to improve themselves and their lives.
BUT, even if the spirit is good, the actual history says that these organisation shouldn't be held on a moral high ground for anything because they don't deserve it.
Moreover, even today, chances are that if you are a non-conforming individual in a very religious community you are subject to isolation, bullying and shaming.
And that's why I find it of very bad taste to use this as a CoC that should guide integration: if I have been bullied from my ultra-religious community, for example because I am bisexual, then I'll not find that a very welcoming sign.
This would then dismiss every CoC-related effort, because most enforcers do little regarding humans being persecuted in other countries...