Without bending over backwards to defend the Linux Foundation, I'll point out that the 97% number means very little -- the percentage that actually matters is the percentage that doesn't go towards funding open source at all. The Linux Foundation hasn't been solely about Linux for decades; they are (facially) responsible for hosting a very large number of open source projects.

one could also argue that software that build on top of it create the ecosystem that can drive linux adoption.

This critique is myopic.