You're telling authors to take away freedoms of its own users now, to prevent a potential bogeyman from taking away freedoms of other users in the future.
You can use permissively licensed code now and forever, because that can't be taken away once released. You're refusing to use it now on the off chance that in the future, someone modifies that code to do something else and give it to other users without the code. Your initial use still hasn't changed, and your right to use that initial code hasn't changed. You are not a user of the new, modified code, so your rights have not been impacted whatsoever.