Since they wrote software under a permissive license, they're explicitly giving anyone permission to do that. I would therefore assume that they're okay with it.
I'm not okay with it, so if I write something I default to licensing it under the GPL (and I recommend doing the same), but my opinions aren't universal.
When Apache board members were busy defending the fiasco that is OpenOffice a couple of years back one of the give away claims they made was that their big contributors abandoned the project because LibreOffice used code from it under the terms of the license and didn't give back.
Not being required to give back being the entire point of Apache's licensing versus LibreOffice.
They (board members) basically refused to make any connection between this obvious hypocrisy and the failure of their project.
I'm not okay with it, so if I write something I default to licensing it under the GPL (and I recommend doing the same), but my opinions aren't universal.