Strange comment given the obvious differences in GPL vs. non-GPL regardless your personal opinion. GPL code means if I decide to distribute my project in the future, I will have to distribute my source code. That isn't a risk I'm willing to take. Some of my projects are open source, but I want to retain the option of doing what I want with my code, so I don't use GPL licensed code.
Why? Do you also avoid libraries with an even number of consonants in the name?