You may exercise freedom of speech but not on server that belongs to a private company - it is their right to limit what kind of content they like.
But in an essence you are right - companies should exist to benefit society, but it is not how it exactly works right now.
Lots of people are saying "But the sites are already exploited" ... they are probably still exploitable further also, and GH/GL don't want to be at that party.
This is not about whether they are legally required to do anything, but whether what they are doing is responsible behavior.
As for being responsible - that is their motivation.
Should I assume that now you have access to this list that you will be contacting the site owners to notify them their sites are infected & exploitable? Would that be responsible on your part?
Their servers, and their decision on what data is on them.
Want to make it available for every to read? Run your own server and host it there.
tl;dr - you have the right to say what you want, but you cant force anyone to listen.