I think permissive licenses are fine in some cases (particularly if you're trying to standardise something. X11, LLVM, and BSD are good examples), but generally at least weak (LGPL or MPL) copyleft are preferred.
I'm still torn on what kind of license is best for operating systems, though (the GPL has forced companies to actually contribute to Linux but they also try and get around it in so many ways I have to wonder if a weaker license would be better)
In some cases, yes. It has to be used judiciously. The free software pioneers understood this, and wrote a little essay about it (LGPL vs GPL): https://www.gnu.org/licenses/why-not-lgpl.html In short, it depends on the market situation: if you created something new and exciting, you should use GPL (nowadays that would be AGPL) to encourage lock-in. If you created something that is supposed to displace an existing proprietary product, you should use LGPL to encourage switching. These days it'd be MIT, but MIT is exactly the same as proprietary as far as user freedom is concerned.
I'm still torn on what kind of license is best for operating systems, though (the GPL has forced companies to actually contribute to Linux but they also try and get around it in so many ways I have to wonder if a weaker license would be better)