I guess the free here is as in freedom as the paid jobs at the BF are indeed paid (and I guess those paid people wouldn’t contribute that much if funding stopped). A link to a better version to get funding keeps your freedom, so the argument is poor I think, but I can understand it looks better to not have Blender to start getting links to paid products everywhere, which would happen at some point if you allow it. Still, it would be great to have the help go both ways to make it sane.
Blender has 2 important types of contributions. The code contributions and the money contributions. Currently, only the later ones get advertisement touching millions of followers through all the possible channels. I think nobody would argue that those companies are cleaner on a moral/spiritual/legal level and thus would owe to have a better treatment. On top of that, even if their funding represents 0.000001% of their monthly income and they decide to stop funding a few month later, they still will have benefited from a nice washing of their image, a lot of visibility and a lot of advertisement. When a solo developer gives a part of his work to the BF, it represents much more to him in proportion than a few 0.0001%.
I’m ok to keep Blender free of ads and links to paid stuff. Ton could still help solo code contributors who do at least as much and proportionally much more with tweets, etc. to help them back?