I think "too Catholic" is just a comment made on the context of what the OP's looking for. I'm sure no-one meant that a Catholic-sounding name was a poor choice in general!
Many people decide to choose a name which reflects their own culture or religion. It doesn't mean they don't like other cultures or religions, does it?
Others just pick a name they like the sound of, whether or not it's connected to their beliefs or heritage.
It's just personal choice and there's nothing wrong with either of the above.
There are threads from time to time, from OPs who are looking for names which reflect their background, or who'd prefer to avoid names which reflect a background that isn't theirs, and this doesn't usually attract comment.
If someone's looking for a Muslim name then they're unlikely to pick a name which most people would associate with Buddhism/Hinduism/Sikhism/Quakerism. So, many names would be "too Buddhist/Hindu/Sikh" not in themselves, but in the context of what they were looking for. It doesn't mean they have anything against the other backgrounds, just that they'd rather refer to their own cultural history than someone else's.
I think since the OP has expressed reservations about using a name which reminds people of a specific religion, then that's why people are saying her suggested name sounds "too Catholic" in the context of the OP's preferences. That's all.