jxself explained it three times and you still do not get it. I am going to
give it a try.
If anyone uses a permissively-licensed code in her website, she is
effectively redistributing this code. Because the license is permissive, she
can choose to redistribute the (modified or not) code under a proprietary
license. The web browser (of a visitor) reading this code is executing
proprietary software. This is unacceptable.
In conclusion, knowing that the original code is under a permissive license
is useless: the website owner, between the developer and the user, can change
the licensing terms.