No, celebration of a completed orbit around our star does not mean we are idiots.
It means that we have managed to determine how long an orbit around the star takes, a significant scientific discovery.
Then we chose a point that doesn’t line up with either the apsides or the solstices to represent “zero” and sticking with our mistake for primitive reasons like “tradition”.
We stick with it at this point because it’s not worth the hassle of changing it, and while points related to our axial tilt or the eccentricity of our orbit are less arbitrary it ultimately doesn’t matter. It is about the time that has passed and one point in the orbit is as good as another.
Any reason to celebrate in a way all participants/affected find enjoyable is a good reason. Not very intelligent aliens.
I’m with the aliens on this one. Celebrating an approximate orbit seems silly but fine, but then we throw so much into it. So many people put real mental trauma on the line because they think one day of the cycle is better for making personal changes than any other. And the amount of money that is spent is just gross. Think of how many people could be fed just for what is spent on confetti - in literally turning useful paper into garbage and dropping it on people (NYC alone dropped 100,000lbs of it last year).
