So the real problem is FUD?

So the real problem is FUD?

Note that this clause is triggered only if copyright holder notifies you. If someone else finds out you are using GPLv3 product incorrectly (something like casual "I see you are offering special version of GCC in your SDK, but I don't see neither source nor a way to request said sources") and you react accordingly ("Oh, you know, we just forgot to upload them, can you wait a few days?") then license is reinstated without any strings attached. You can make mistakes as many times as you want till the actual copyright notifies you of the violation by some reasonable means.