It's the grandiose, self-congratulatory, hyper-ceremonial pomp and circumstance of the situation.
It demonstrates a total lack of humility. So your baby-oven functions properly. Whoopee. It can produce either of the two standard flavors of human. Big fucking deal.
You know why so many traditions are ancient? Like, rooted in versions of themselves that are at LEAST centuries old, if not millennia? BECAUSE STARTING NEW TRADITIONS IS AN INTRINSICALLY EGOTISTICAL THING TO DO.
Following old traditions isn't just something you do because you're "supposed to." When you follow a venerable tradition (as oppposed to a trendy fad), you are communicating that you understand your place. You're just one human in a long chain of humans, just like yourself in every important respect. You're affirming that you understand you're truly not anything special, and neither are your offspring. And that's A GOOD THING. Most people aren't special. People have intrinsic value, as EQUALS, and it's good when we recognize that.
Jumping onto a newly-made, bandwagon tradition like this one (especially one that is openly self-aggrandizing) indicates that you think in the opposite fashion. You think you're the hottest of all the hot shit. You think you're the main character.
If you think that way, you're simply a bad person.