And it doesn't matter about being 60+ ilvls above the gear you can get from them, fact is the bosses still hit harder than anything up to and including T11 normals in Cata (probably beyond but I've not attempted T12/13 yet) and they're much higher level at the same time (meaning more armour and higher defences etc.) so it's not "expected" at all for that particular reason. But if you knew anything about shammy soloing you'd realise how tough it can get, and the fact that tactics need to be developed for stuff that is facerolled with 5 people. (so stop trolling and bashing my feats)
oh and btw, the mobs in normal scenarios hit for the same as the mobs out in the world do...so I can't see the heroic ones being too tough either (in fact the only time I've died in the hc ones is when I pull too many mobs w/o cd's or miss a mechanic etc.) - the only reason I haven't done any scenario soloing yet is because of the stupid amount of hassle it takes to set it up, given there's no way to enter w/o queuing.