First off I want to say I don't condone the cheating/duping etc. at all and I don't know Minidragon at all either (other than seeing him around occasionally).
To the OP... I understand your point about a good player not cheating, but I really think you did not read Mini's post all that well.
([link=http://nineinchninjas.com/forums/viewtopic.php?f=63&t=9103]http://nineinchninjas.com/forums/viewtopic.php?f=63&t=9103)[/link] The things he says seem to be contrary to what you seem to think he said.
His point is that playing your job the right way is the most important thing and gearing the CORRECT way is also important. He mentions that there is alot of good free gear in Campaign, he also mentions Sea gorgets (also free). While they (NiN) were gear whores and went about getting some of their gear the wrong way, he makes some very good points.
Personally, I think it is important to criticize the gear we TP/WS/Enfeeble/tank in... and I am constantly asking people I think know better for suggestions. For example... I have been messing doing SAM/THF recently for NMs/sky and stuff and have developed different gear swaps for TA/SA after talking to a THF who also had PLD geared. He suggested using some of my +str/+enm gear with my TA's instead of just +str... a totally simple thing that increases my effectiveness. It's not 1337 gear, but it definitely increases00 the function of what I'm doing.
I have also started tanking sky gods... and asked the exact question about gear blinking to my WHM/RDMs. I didn't want to do too much of it, however they said the same thing Mini does... blink as much as you want if it will help, don't worry they would adjust. Also, found out after my first run that if I adjusted what was swapped when (gear I already had) I'd be more effective. Someone gave me criticism (positively/constructively) and the next time it was WAY easier.
Basically he was saying a good/smart player can probably match the damage output and/or effectiveness of some pimped out stupid players simply by making wise gear choices. Just because you didn't cheat to earn your God gear or whatever doesn't mean you're using it the best/right way (As SAM I've out parsed a God Geared SAM who didn't gear swap, with my "cheapy" AH stuff and good gear swaps). I have been willing to accept criticism to make myself more effective with what I've got.
To sum up...
Did Minidragon deserve to get banned? Yes
Does the fact that he cheated mean we can't learn anything from him? No
Has OP gone overboard in his criticism: Probably
Is all criticism bad? Not at all when done right