Boot cut can pass styleforum muster if done right. All of the wjk and junhashimoto extra heavy jersey pants I own have a cut and drape similar to that of the Japanese guy's pants shown in the last picture that Uncontrol posted above. Because the cut is subdued, you can barely tell it's boot cut from the front or rear views. Only from the side profile is it overly noticeable.
With certain outfits boot cut can actually look better. For example when pairing an over sized jacket (e.g. M65) with the forum's preferred jean fit of "tight at the ankles" the overall silhouette can look unbalanced, top heavy, and peg leg like. Whereas the same bulky jacket paired with the right boot cut will still look slim in the legs but the wider bottom hem balances things by providing some additional bottom heft.
Most of the things people hate about bootcut jeans, which tend to be shitty washes, stitching and processing, don't have anything to do with the cut at all – though mall-brand bootcut is usually awful.
wjk has the most SF-friendly examples.