What I am proposing is that Wikipedia infoboxes should be included in Wikidata

this is good proposal, but it is far from what we have and not clear if it will happen.

But now unfortunately the Wikimedia foundation has a motive to block such a proposal, in order to not threaten their revenue stream

And that's the problem with making money off convenience. If the free thing becomes better, then it cannibalizes the paid stuff. So if you take this approach to funding, you will want the free tier to be perpetually bad as much as possible.

I think sorting current infoboxes mess is not trivial problem. We will see what will be quality of their solution, it could be lower than actual wikidata.