To be fair it's not just catholics, the whole lot of Christianity is in error with things like this.
If I tell my son not to participate with something, and some bad people lured him to do so and to not get in trouble he does it in honor of me, would I be any less upset? No. I told him not to and he did it anyway. God tells us not to participate in things like that, you think putting his name on it and making it about his birth makes it any less evil? Same with easter.
And the problem comes down to some people's rejection of the authority of the Church, the entity that was set up here on earth to decide things. Whatsoever is bound on earth is also bound in heaven and the Apostles passed this authority down to their successors in the Church. Miracles didn't end with the death of the Apostles and neither did the authority of said Church here on earth either.
Ladonia, there is one thing I appreciate about you. You are honest, this is a genuine Roman Catholic belief and you stand by it proudly. Problem is it's a distortion. The Church is the pillar and foundation of the Truth, but the Truth is still found in Christ, He is the cornerstone of that foundation after all. If the Church deviates from the Truth established by the Lord, it doesn't mean the Truth the Church stands on remains as Truth, it means the Church is no longer the foundation of it. You're saying the apostles and bishops had authority handed down to them to declare such a holiday as righteous, despite the Lord saying differently to Israel in the Scriptures, and that's a big error. If the Church deviates from the Will and Word of the Lord, they deviate from the Authority as well. It's but another reason I can never claim Roman Catholicism.
My issue with Christmas itself is making it into a religious event, and even more so an event with something to do with the Lord, and this is a nono since it did originate as a pagan festival, and no sane man would think putting His name on a pagan holiday would receive His approval. I would celebrate Xmas if it was purely secular, a holiday meant to bring good cheer and family gathering, good food, things like that. As a religious festival, no.
There's no indication that the Lord was born in December, nor is there any indication that the disciples honored such. It's purely a precept of man with paganistic rituals in it, done in the name of God.