You misunderstood the idea of rejoining.
Let's say you disconnected in the first few turns, and that game just isn't ever going to happen again within the next week. It's the only decent game you'll find.
It should be an option of the host to allow people to return despite problems x,y,z. It keeps the fun going.
all people want to do now-a-days is stop problems from happening. You can't do that. Eventually, there might be so many patch jobs on problematic situations that we'll never know who the bad guys are. Kind of like forcing kids (and gangsters) to wear uniforms; you don't know who the troublemakers are. Everyone looks the same.
Every good society needs to have the distinction. Rejoining trolls have not been the biggest problem from what I can tell, and in fact rejoiners are one of those trouble making kiddies who we need to know the names of. Otherwise they'll not be well-known enough for us to bar from games.
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"Do not pray for an easy life, pray for the strength to endure a difficult one"