The only way I can see this being dealt with, is if it is added to the rules. Then we can do regular checkups to see if the players respond, if they don't, give them another chance or two, if they still don't then kick them or something.
Fine by me!
Even suggested something to temp lock a player till he answers a big message. Not cause we need the reply, but because we want people to teach stuff and afaik a lot of the new players don't read. Forcing them to reply, will make sure they have reached the messages. Would prevent a lot of (vote)kicks and would be good for the playerbase. But I guess this is not only PUG related.