It's also blatantly the exact opposite of what companies have always done, back to the early days of BSD Unix, which is use software licensed under simple, permissive terms to base proprietary codebases off of. Them making that claim must be in bad faith, given how absolutely contrary it is to reality how it directly attacks a reason people don't use those kinds of licenses.
I could bring up how proprietary software companies go out of their way to insult the GPL by calling it "viral" but the breathtaking dishonesty of that argument alone makes my case for me.