This is because an analogy is in fact a form of fallacious thinking. Except in the case where your analogy is effectively an argument to generalisation, attack

This is because an analogy is in fact a form of fallacious thinking. Except in the case where your analogy is effectively an argument to generalisation, attacked via a specialised example (but arguing only over the generalisable properties). Any other type of analogy immediately falls flat as soon as someone calls out specialised property x that does not hold for oroginal argument y.