@BlueMythril I could see blocking players that are rude or quit games... but you would actually want to block players that are aggressive? Why play against players that don't use Catan strategy to their advantage? Seems silly to play a game only against weak players.
But yes... A block would be great for these quitters. Blocking them is even better than dropping their ELO... if they get blocked enough they will have nobody to play with.
I just blocked 2 players who where either teaming together or clueless because they were placing the robber on the losing players, I am a competitive player and have no tolerance for level 20 players that target the losers with the robber.