Just like anything else it takes practice.
I brewed for years but quit a couple months back. Going All Grain and utilizing a fermentation chamber to control temperatures of different stages in fermentation allowed for a vast improvement in quality. I thought most of what I brewed was very good, some was less so but it was fun to experiment. I mostly brewed what I wanted to brew but I did several commercial "clones". In blind side by side of Founders Breakfast Stout and my homebrew people couldn't tell the difference, I couldn't tell the difference. My Zombie Dust recipe was pretty damn close, a little hazy, but when compared to the real thing it was basically there. You can absolutely make good homebrew.
Home brewing is great. In hindsight having 5 taps in the basement with 25 gallons of beer on hand at all times turned out to be too much so, I brew no longer, at least until the kids get older
EDIT: Oh yeah I tried Colby's IPA a couple years ago, he did a good job