Thoughts on the decision to force .org repo themes to use the Theme Customizer:

Freemium themes that were in the WP.org repository will lose customers.

Customers are used to configuring themes one way, then have to learn another. Some themes are broken, because of how options are saved. This will drive people to ThemeForest, which they understand.

Users want themes to "just work", even if this means their sites are insecure, because the bundled plugins don't update. But this is not anything they worry about. They just want to buy a theme and have it work. They do not want to hunt down plugins. This is the whole point in using ThemeForest and not hiring a developer in the first place.

But I think the powers-that-be in WordPress have a long-term plan.

They have no interest in launching a commercial theme marketplace to compete with ThemeForest. This would be too much control, and TF is already established as the destination for themes. No, too many problems that direction.

But to grow WordPress from 25% to 50%, it will be a lot tougher than 0 to 25%.

The platform will need to seen as secure, reliable, and not buggy.

ThemeForest themes that are bloated and insecure work against this goal.

To work on security, they must convince theme authors everywhere to unbundle plugins and themes. The customers have no knowledge of security, they want convenience.

How to make ThemeForest authors change their coding practices? How to make themes everywhere just a bit more secure?

Step 1 is change the .org theme repo policies. Free themes that have Premium upgrades must evolve or compete elsewhere. But this is not enough by itself.

Step 2 has to be educating the customers to the separation of plugins and themes. This is the most difficult step, because they must unlearn what they already know.