>open source projects have become dominated by tools, libraries, etc that support a proprietary end product,
One look at Github proves this to be fact
> it would make more sense to me that most of those tools would be released under the GNU GPL so that the original author can incorporate it into their own proprietary software
No infact it would not, because if they accept code contributions those would be GPL with a copyright attached to the 3rd party developer, and if they then incorporated those into their closed code base they would be in violation of GPL and the 3rd party dev could sue them, This has happened many times
Some organization attempt to get around this is CLA's but CLA's are universally frowned upon and completely kill contribution from 3rd parties as such most Open Source projects that operate with CLA's end up having very few contributors that are not being paid directly by the primary company behind the project.
CLAs are frowned upon by some, but they don't completely kill contribution from 3rd parties. I've signed plenty, and I've encountered plenty of projects that use them that continue to have a good community of outside unaffiliated contributors.
There is no if, my premise is a fact
>open source projects have become dominated by tools, libraries, etc that support a proprietary end product,
One look at Github proves this to be fact
> it would make more sense to me that most of those tools would be released under the GNU GPL so that the original author can incorporate it into their own proprietary software
No infact it would not, because if they accept code contributions those would be GPL with a copyright attached to the 3rd party developer, and if they then incorporated those into their closed code base they would be in violation of GPL and the 3rd party dev could sue them, This has happened many times
Some organization attempt to get around this is CLA's but CLA's are universally frowned upon and completely kill contribution from 3rd parties as such most Open Source projects that operate with CLA's end up having very few contributors that are not being paid directly by the primary company behind the project.