Lack of citation and data noted. I'm assuming good faith and going to approach this as I would a fellow colleague :)
I'm also going to assume you perhaps haven't been introduced to the vibrant ecosystem of permissive licensed software.
The article also doesn't mention how GPL is a show-stopper at some companies where we are building proprietary solutions.
Oracle, IBM, Sony, Apple, Microsoft, Boeing all are monetized empires that profit not just from binary blobs, but from providing a superior product. Also, being the patent holder is lucrative.
How do you intend on running a business and feeding your employees, let alone making investors happy following the virtues of GPL? Consulting and support only goes so far.
> Most of them are stepping stones towards further software development.
Ever hear of DragonEgg? (GCC was used to bootstrap LLVM/clang in it's early days.)
Devs use GPL software to write permissive software. Sometimes they do so because they have no choice but to reinvent the wheel because of GPL's rules.