It doesn't make the COP useless. It takes away its value.
I'm not completely against them releasing a vanity helm. I'm just against the fact that this vanity could possibly replace the COP's idea of rareness and value, thus minimizing the effect of what the 56 Grinding Cap was like for a few older members of the community.
We had to go through times without 4x combo, which about 80% of the current endgame community has grown up in PL around and with their first character, seen people pop them all the time.