Where they are disliked it tends to be because they push the "fruit" angle with their name and packaging but have a much longer list of ingredients (Example: water, blackcurrant juice (5%), cloudy apple juice (4%), citric acid, acidity regulator (trisodium citrate), flavouring, vitamins (C, niacin, pantothenic acid, B6, D, B12), stabiliser (xantham gum), preservatives (E202, E242) sweeteners (aspartame, acesulfame K), colour (anthocyanins)). It's equivalent to paying well over £20 a litre for juice.
I don't think fruit shoots are hated more than other simiarly misleading stuff, but they have become a kind of MN shorthand for this kind of misleadingly-packaged, additive-laden product.
(Why does something sold in and drunk from an opaque bottle need colour added anyway?)