well I agree with you to some extent ...
What I dont agree with is going to one raid and gearing yourself in gear thats better than rank 14 items ...
I can tell you from my 5 months of clearing MC and Ony that items just dont drop for us .... we never got Bonereaver's Edge and we killed Ragnaros many many times, Mageblade .... 2 times dropped, like we just dont get mage items, some T1 items never dropped like ... boots for warriors only 1 dropped 3 weeks ago, warlocks ... first last week ... and so on.
So I would say that if you arent lucky it will take you few months to gear up.