Only you can decide who to be friends with. I'm certain you enjoyed spending time with these individuals even though you disagreed with their behavior otherwise you would have stopped it a long time ago.
At the end of the day you decided to be friends with them for 10 years and ended it childishly through a messaging system. Even with their behavior you need to man up and talk via call or in person. In time of despair sometimes you need to be the better person.