I don't think damage received is necessarily the best benchmark else you'll see reverse scaling in effect (which is a very bad mechanic). What I mean by that is - if one of the stratics for placement was dependant on how much damage you take, then a tank with lesser gear would end up placing higher than a tank with better gear; unlike any other character type.

Now if threat generated was used instead, then you shouldn't have that same problem. If they limit it to tanks getting credit for threat (as opposed to DPS, who could effectively 'double stack' with damage and threat) then we start to see people getting rewarded for doing their job.

They have said that tanks are supposed to be getting credit for doing their job just like everyone else. I believe it was one of the things they were working very hard at trying to balance out. In the end we'll have to see how effective they have been at doing that balancing act - but they are keeping tanks in mind.