I had never used the Auction House when I *first* completed Inferno. I almost bankrupted myself with repair costs when I soloed Rakanoth but the feeling was one of immense achievement. I can solo all bosses with self-found items. Of course, my WD died many, many times.
My most godly possession then was a blue belt with 2.8% chance to freeze on hit which worked extremely well with Road of Toads. I don't use that belt any more (too crappy now) but I kept it in my stash for sentimental reasons. I can't bear to sell it either :))))) Nobody would want it anyway.
However, when the MP system was introduced, I had to use the Auction House for "upgrades" to play at higher MP levels. I don't have any farming gear on me. I use Blackthorne's Notched Belt occasionally for that extra gold find but hardly use it now as the damage was not sufficient. The only farming "gear" I have now are from the Paragon Levels.
My only godly finds (IMHO) were Witching Hour, Zunimassa's Trail and Zunimassa's Marrow. The rest, I had no use for (e.g. the Manticore on my Scoundrel) or were pretty crappy. I have had zero luck for Zuni Pox or Tal Rasha Allegiance. I had to bid for a cheapo Maximus for Eirena but it was worth it.
I play the GAH to get some extra "income". It is not much but it helps pay for my repair costs, gem crafting and some items which I want for my toons or my followers. Last minute bidding in the Auction House can be very exciting when you want the item so badly.
When I need help in ubers at higher MP levels, a clarion call for aid will bring in some uber players who will willingly clear out the bosses in no time. No need to second guess where some of their uber gear came from.
I have nothing against those who use the Auction House or those who don't. I admit I still have ambivalent feelings towards the Auction House. Damn if I use it, damn if I don't.
Like I said earlier, I play whatever I like.