Copyleft does not solve the problem: how to build a positive business cycle. No company seriously contributes to the copyleft. That is why the Apache License is raising. And you can see that all changed licenses mentioned in the article are not copyleft. Copyleft is great for licencors, but most of companies in the world, does not want to share their customs. This is the businesses.

The Linux kernel is almost the only one in the world and cannot be copied.

For business, the copyleft is combined with proprietary license. So business gets "pro" version with no copyleft requirements, while open-source users get the same code under a different license.

And a lot of the companies mentioned in the article have moved to BSL, which _is_ copyleft (after a few years of delay), or to SSPL which is arguably even more extreme copyleft than AGPL.

It's misleading to call the BSL and SSPL copyleft, because while they are viral, they're not free.