Why is mixing good whiskey with cola/ginger ale frowned upon? I ordered a Jameson and ginger ale at a pub the other night and my brother asked me why I wasn't ordering it neat or on the rocks, since it was "pretty good" whiskey. Right now I'm having some good Kentucky bourbon (Willet) with Reed's ginger ale. Is this "wrong"? Does it matter if the ginger ale is good? 

I know that this could be considered an opinion question by some but I'm asking if serious whiskey buffs would scoff at this or if they have done so in any specific literature. You know...collectors, bartenders, distillers, etc. What is the reasoning behind the common practice of discouraging mixing good or better whiskeys?
It is about the same thing as putting A-1 on prime rib. Mixers, like cola or ginger ale, tend to mask the flavors of the whiskey, something which is understandable for an 'inferior' brand but is thought of as 'taboo' for a 'fine' blend. The drink that results from mixing your fine whiskey with the mixers is (roughly) 'the same' as if you had mixed a cheaper blend, having concealed the subtleties that aging and craftsmanship have worked to create. 

That said...if you like it, it is your drink.