Is net neutrality a regulatory requirement that ISPs cannot block or slow or throttle access to any particular website?

And the response is "who cares, ISPs will respond to the desires of their customers and will compete?"

If that is the general argument, then in this case the interests in free speech and free association that are implicated are too important. Regulate it and don't give any ISP a chance to respond to public pressure by, for example, blocking all access to LDS.org because some liberal group thinks we're LGBTQ "haters."