If you define it that way you are right. Yah. But the common understanding is a bit different than yours.
https://en.m.wikipedia.org/wiki/Operating_system
Really great read.
I urge you to take a look at https://www.debian.org/ports/kfreebsd-gnu/ It’s the exact same utilities and everything but a completely different kernel. It really highlights the difference here. How would your definition account for this?
Would Debian GNU/kFreeBSD be 50% Linux, 50% FreeBSD under your definition even though it has no Linux code? It has all the system libraries and system utilities that you associate with Linux.