A support employee is useless if he doesn't have access to actually solve problems, but an anonymous service can't just give such access to any "support employee". There's a lot of trust involved.
At some point, blinded bearer certificates will be used, and the mixer will be decentralized so that there will be more than one member managing the multi-signature escrow address, not finding a trusted person to manage technical support is a big problem.
In addition, it is not useless, it will reduce the burden on admin/s and organize all requests for them. admin job will be to respond to support requests instead of reviewing messages and responding to them individually.