This has always been something I wish most ARTCC's managed better was TMU. You see it over and over again traffic levels far outpace the controller capacity, network capacity (voice), airport capacity, etc...
A lot of people aren't mentioning this, what about staffing levels the event ARTCC has? If an ARTCC can only staff one guy on finals for a position that can fit 3 final controllers, what is his limit? I personally feel anytime you get more then 10 pilots on your frequency for a very busy sector (vectoring, finals, arrivals, etc..) due to voice and network limitations you can quickly lose control over sequencing. The pilots are NOT professional pilots and thus add to more radio calls being necessary also.
Many times when working ZTL (non events) I and a few other controllers would simulate re-routes due to weather in the ATL area. You would be surprised on how many pilots participated and LOVED the fact we were simulating that! We occasionally would get the pilot who did not want to participate and we would just send him on his normal route no questions asked. So while many in this thread are afraid pilots will not want to sit on the ground, or just disconnect, yes some will do that, however I think you will be surprised on how many would actually like that.
Also how many times have you seen a FNO where they have 4 center controllers online but only 1 is super busy why the other 3 are twiddling their thumbs??? ARTCC's need to be able to recognize this and take initiative on opening up further sectors, rerouting traffic, something. Again using ZTL as a example since I am the most familiar with it...They use 1, 2, 3, next to their position name when staffing a position. Why you may ask?? So that if you have 4 center controllers online they can very quickly switch frequencies to open/close different sectors without having to log off and change callsigns. To this day I really do not understand why other ARTCC's have not adapted this policy, it works wonders.