You say they're dumbed down, but then you go on to describe all the tactics you had to use to complete them. This isn't Wrath - they aren't adding heroic 5-man content with each content patch. You can gear up to 60+ ilvls above the max gear you can get from heroic 5 mans - what do you expect? Solo the current heroic scenarios in 5.4 and then you can complain about soloing heroic content in the current expansion.
They're dumbed down for the intended audience of 5 player groups, the very fact that I could solo them (without being a DK also) in the middle of the expansion is testament to that - try doing that at all in any other expansion, in Cata for example the normals were difficult to solo at the end of the expansion (heroics were impossible).
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.
Point is: The role of hard 5 man content isn't filled by heroics but by challenge modes. The heroics were never intended to be as hard as in expansions past as they're more a convenient step in the gearing process than a way to entertain people seeking to overcome difficult content.
That said I still say good work on soloing them.