I… put my coat inside my bag. Whether a carry-on or checked. Even if I go to a cold climate I will have my bags before I walk outside the terminal. I can stop, open my bag, and grab my coat. I don’t know how that’s skirting around it.
If you don’t want to wear it, cool - then put it in your carry-on or hold it for the flight. At the very least wait until everyone has boarded and there is room. Taking up space in the overhead while people are still boarding is selfish, it’s saying “My bag and my coat deserve more space than the next person’s single bag”.