Its internal legal departments of large companies (and some medium sized ones). They tend to be most highly concerned with the patent provisions in GPLv3, and y

Its internal legal departments of large companies (and some medium sized ones). They tend to be most highly concerned with the patent provisions in GPLv3, and yes, GPLv2 is much more palatable, though I've often seen requirements that the code is not contributed to. The denial is not from the GPL it's from the corporate legal team. This is a big reason why the Apache 2.0 and MIT licenses are much more popular among tech companies with private codebases (in addition to the Open Source code that they release).