[ericb]

The open source from your list largely falls under #1. They didn't open source their primary product, but rather their complements. That is sustainable, whereas #2 is not when a permissive license is involved.

Strategy #1 is self-interested and doesn't require any real zealotry and survives the harvesting stage just fine.

Open sourcing your core product with a permissive license is generally going to be at odds with business goals at some point, and if you're in business, often the thing to give is the license.