You wouldn't have to ask this question if you didn't practice this tradition of man anyway - which is exactly what it is. Birthdates are astrological and used for magic; laypeople believe it is just a celebratory day representing the Day one came out of the birth canal. Day of conception would be more appropriate, but no one believe life begins then.
When you apply worldly things to something already fixed, you get a messed up product. When your "fixed thing" is Christ, it becomes abominable. You are arguing emotion right now.
Your Father warned you several times about being in the world, and doing abominable things dressed up as holy. I am not going to argue you down; you do what you want to do. My job isn't to save YOUR soul because someone has already given you a way with better directions.
And let me just say this about your point: people are of ignorant of the world around them all of the time:
You likely wouldn't know Saturn if you saw a black cube rotating counter-clockwise on an axial point, a hobeycomb, or a hexagonal mapping.
You think the stuff is ridiculous, which is why if anyone is into it YOU would be easily exploitable. You wouldn't be able to see the astrological connection between your birthday and prominent persons, and how that is exploited against you by people who use real magick (whether you believe or not). Laypersons believe they know about the "silliness" of occultology, but I can tell you wouldn't know what abominations are around you. If you can't see the symbols of Christmas painfully boring an offensive hole in your spirit, then you can't understand why people are attacking the enemy, and not you or your pet holiday. If you can't immediately see what image, for example, an evergreen with a star on top represents in geometry, and occultology, then you don't know your enemy fully. Arguing with people who are seemingly attacking your fav/personally invested worldly holiday is par the course; I did it against people saying this 20 years ago, before I came to.
The Most High God gave us several holy days to follow, and we as a lot ignore ALL of them. He never mentioned celebrating birthdays; as important as it is, Christ never mentioned His. We do the worldly celebrations specifically abominable to Him, and then we have the audacity to ask if HE CARES when our lives are in chaos. Moreover, whenever someone on a layperson Christian TEAM tries to tell you something, it is taken as a twisting and heretical assault - not concern or care.
Not only that, but our eyes are crusted over - keeping many from seeing how they are being exploited by the enemy they help. So, do what you want to do. It is your life, mind, and you choose how to rationalize it all.