having character collision is a bad thing. people can use it to grief others. Its was a huge issue in dcuo when people would block hallways or take hostage players. pretty much trap them in hallways.
If you ever played ffxi you will not enoy CC if it had it. There is always a wall of players blocking mog houses.
even ffxi had buffers from signet (def + etc) IS had isp buffers of all sorts even a exp reductions on death same sad wings with their signet thing.
players created the camps not the game.