Don't normalize kicking people out of your posse for no reason an killing them

Yesterday I joined 3 different posses via posse up. Not even a minute in the game and I get kicked out of the posse for no good reason. Just to be killed. Whyyyy? I just want to play and I always do my best to help in missions. Please just don't make an open posse if you don't want people to join :'(