If they took away the auto follow, this would definitely help stop some of the leeching.

Think of it this way... there are not enough mobs or quick enough spawns for every person to kill solo, and some of the mobs would die so quickly you are waiting for more spawns. Being in a party like this helps maximize the SP per person, while keeping the spawns so you are always killing something.

Another solution to this issue, is making the mobs harder. Requiring more members to be active to be able to kill the mobs. Seeing as mobs can be killed with 1 or 2 members easily, it makes this easy mode and half the time the other members don't get to attack it anyways, or would cause issues when they attack.

Also, just cause your following doesn't mean you are AFK

The game allows it, so don't hate on it. I would prefer if they got rid of the ability to do it, but until then... Do whatever is best for you and/or Your LS.