Interesting approach, but I bet those companies also aren't high growth tech startups/companies. The only goal at a growing tech company is reduce costs, increase revenue. They aren't looking for new ways to pay for things they legally get for free.
My favorite example is Redis at Twitter: Twitter has over 30,000 Redis servers deployed around the world using a total of over 500 terabytes of RAM (half a petabyte!), and they certainly have no interesting in paying for Redis. If Redis were typical "commercial software" licensed per-core or per-other-shennigans, they'd be paying over $70 million per year for Redis.
(Redis is a unique position because the core dev team of Redis has always been small so it's easier to measure the direct exploitation involved versus other projects with thousands of amorphous developers like Linux or Hadoop or Apache.)
Many open source projects are essentially corporate welfare. We work, make products companies use to make money/become more efficient/grow faster, the companies use the software for free to get richer, then nobody contributes back any of the gains.