The Economist ("Profiting from obscurity: What the 'long tail' means for the economics of e-commerce") cites Chris Anderson's "The Long Tail" as reminding us the when and where there are very large numbers of choices, markets will rise to the occasion and develop tools to help buyers cope and sort. Amazon and Netflix regularly guide customers through their huge inventories ("customers who have bought x also like y"). Search engines, likewise, are getting ever more helpful in this endeavor.
Indeed, the discussion highlights the fact that niche markets in the the "long tail" will emerge and many will prosper as enough buyers are guided to the non-blockbuster and less popular speciality items. It is win-win.
So, on reflection, the naysayers are even more wrongheaded than one would have thought. Of course.