No,it's not. At least not any of it I ever tried to drink.
I've had corn whiskey so smooth I could pour it in my doberman's water dish,and she would drink it all without raising her head. She loved beer,but she would refuse to drink any other whiskey. She got drunk on it once and fell down the stairs and hurt her leg,and wouldn't drink it any more for a couple of weeks.
Of course you had to be REAL careful to not piss her off after a water bowl of corn whiskey.
The best is not available in the stores. It usually comes in gallon milk jugs these days.
There used to be a store-bought brand titled "Cobbs Creek" that was passable,though. I used to drink in when I was living out in Denver,and cut off from civilization. I did have some friends bring me several gallons fresh from the still in Georgia though,and it really opened the eyes of my Denver friends that had only heard government rumors about how it would make you go blind,and other nonsense. They all agreed it was the smoothest whiskey they had ever drank,and that they didn't even know straight whiskey could be that smooth.
The problem is the taxes the government puts on it. You could make and sell some seriously good whiskey for 30 bucks a gallon retail back in the late 70's and make good money doing it,but if you wanted to sell it in the state stores and pay the state and feral taxes on it,you would have to sell it for more than 100 bucks a gallon to even come close to making the same profit per gallon. That's why whiskey store whiskey isn't that good. They have to make it at a level where people can afford to buy it,and the taxes make it hard to make and legally sell good whiskey.
BTW,not all of it is good. Some really is as bad as the government rumors claim. My father made the money to buy his first new car,a 1952 Ford,by making and selling white whiskey he brewed in he attic of a house we were renting. Since he was never a drinker himself,and I had tried the wine he made later in life,it had to have been some gawdawful stuff. Still,in 1952 he was selling it for 50 cents a pint and making a hell of a profit.