As far as I know, this is case for most GNU projects.
Linux only requires a confirmation that you wrote the patch; previous poster was mistaken about that, but they were correct about GNU.
The Free Software Foundation may publish revised and/or new versions of the GNU General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns.
Each version is given a distinguishing version number. If the Program specifies that a certain numbered version of the GNU General Public License “or any later version” applies to it, you have the option of following the terms and conditions either of that numbered version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of the GNU General Public License, you may choose any version ever published by the Free Software Foundation.
And so when you see things like https://directory.fsf.org/wiki/Coreutils
Note also the "if you used the GPL without a version number, you can relicense it under any version"
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The "why they require a CLA" is for enforcement.
https://www.gnu.org/licenses/why-assign.en.html
In order to make sure that all of our copyrights can meet the recordkeeping and other requirements of registration, and in order to be able to enforce the GPL most effectively, FSF requires that each author of code incorporated in FSF projects provide a copyright assignment, and, where appropriate, a disclaimer of any work-for-hire ownership claims by the programmer's employer.None of that seems like a "why" to me; to cynically paraphrase it, "our policies require our polices." Why does your record-keeping require a CLA? Why is a CLA required to enforce the GPL?
At this point the GNU foundation mostly just runs relatively small, older projects and that definitely does not include the linux kernel. That one has its own foundation called the Linux foundation. The Linux foundation runs many hundreds of projects and they operate mostly without contributor licenses as far as I know. And in so far they do those agreements are not about transferring ownership of the copyright but asserting ownership to ensure that the contributions people make are actually legal.
Big corporations moving code bases under their control seems to be a regular thing and that includes some pretty high profile projects recently. And of course there are many more projects on Github that use one of the GPL licenses. The vast majority of which don't have any contributor license.
So, I don't think I'm that wrong here at all that this is not that common. The previous poster seems to confuse the license with the GNU foundation which is a tiny subset of the overall GPL licensed software ecosystem.
No one claimed this is the case. The only person conflating "GNU" with "GPL" is you.
You said projects with copyright assignments should be distrusted. Someone pointed out that GNU projects require this, which you promptly denied, and I just wanted to correct the record on that. Nothing more, nothing less.
You mean the GNU Project.