Just like there is a carbon tax to care about making oil companies care about environment, the "Open Source Tax" would be a tax, that is applied to companies for using open source software, and re-distributed to foster open source ecosystem.
Maybe there should be also research tax, cause researchers (esp. in public universities) create good for the public.
There does need to be a way to re-invest in open source software. I thought of an open source subscription before. But getting people to pay for it when it seems free....