And if you think the tool would lead to you wiping, then, as stated, you're more than welcome to not use it and continue to run only with people you know and trust. If you're that hardcore, then you won't even need the tool anyway because you'll be too busy with the current tier.
Oh my...let's see, you have the bear boss in ZA where you have to coordinate people to step out of the group so that the healer doesn't get mauled (and again on the last boss), you have the guy who calls out the hatchers and you need to coordinate who's going to go take them out, you have Jin'do which is all about kiting adds off the healer while others nail burst damage on the chains and the tank controls the body slam things, there's plenty. Not even just in the Zul's, hell, look at some of the regular heroics. The 2nd boss in Blackrock Caverns with the laser beams, the high priest in Halls of Origination you have to coordinate big time to pull the levers and keep someone up top to interrupt...
Players have learned and improved A LOT by doing these encounters and they are most definitely ready to be able to PuG raids that are already nerfed and that they already outgear.
Pre-nerf these instances were being flown through by guilds in 346 gear. Now they have been nerfed and the minimum ilvl I have proposed is 351. Thank you for proving my point.