Although I prefer American whiskey I have nothing against scotch, despite my occasional pokes at some of its more pretentious enthusiasts. My real quarrel is with the ones who denigrate and dismiss as pretenders all whiskeys that are not single malt scotch. Their prejudices, like most, are generally based in ignorance.
One of their false beliefs is that spirit distilled in pot stills is inherently superior to spirit distilled in column stills. Because most American whiskey is initially distilled in a column still, like Scottish grain whiskey, many scotch enthusiasts assume they are more or less the same thing.
First, the stills. A column still can do anything a pot still can do but it can also do things a pot still cannot, like distill to 95% alcohol. It's not the type of still that matters, it's how you use it.
Second, the second distillation. Like Scottish single malts, American whiskeys are distilled twice, the second time in a pot still. Although the Americans don't need that second distillation to raise the proof, they believe it polishes the whiskey by pulling off a few of the more stubborn undesirable congeners.
Third, the end product. In Scotland, column stills are used to make blending whiskey that is distilled just shy of 95% alcohol, meaning just shy of neutrality, i.e., vodka. Pot stills are used to make malt whiskey that is distilled to about 70% alcohol. In an American whiskey distillery, column stills are used to distill to about 70% alcohol, about the same as a Scottish malt distillery. (Lower proof off the still means more flavor in the green spirit.)
The two distillates are different because of different grains, different yeast, and different water, but not because the stills are different.
The Celtic (Scotland plus Ireland and Wales) and American whiskey-making traditions began to diverge more than 200 years ago. They're different, you may even like the product of one better than the other, but to claim that one is objectively better than the other is calumny.