But Linux is GPL! And Linus himself believes Linux wouldn't have become what it is now if it weren't for GPL.

In the context of Linus values, open source means basically the right of forking software, but copyleft means the right of merging back worthwhile patches from downstream forks. This is absolutely critical in an industry full of binary blobs: this is basically the reason we have any kind of source code for Android kernel drivers, routers, and many other products.

What Linus doesn't value is the goals of free software movement: empowering the user of the computer. He just wants the code. That's why he doesn't care about tivoization, but he cares a lot about GPL.

It is probably more about a v2 vs v3 debate in the case of Linux. He really likes copyleft GPLv2-style and really thinks it has been a net-positive if not one of the key things for the success of the project.

This was part of the v3 fight - he wanted software free, but also so you were free to use it. Didn't mind that you could use it with locked down hardware (TiVo / cars / phones / med devices / security etc)- still had to release source