> Any sufficiently useful closed-source program will be cloned into open source in today's environment.

That is a parasitic and unsustainable model. Even if you could find enough volunteers to copy the work of every bit of successful commercial software, that original design and development work still needs to be funded.

Other commenters have noted the quality situation of many of the cloner projects out there. Even cloning takes work and sustainable, quality work needs remuneration.