I like to use such analogies, but have actually found them very limited for persuasive purposes, or only very effective with certain kinds of abstract thinkers.
Of course, if you already agree with a speakers' point, the analogy makes sense and helps make the matter vivid.
But when a listener intuitively disagrees, the analogy can derail discussion. Even though in the spirit in which it was offered, it aligns one axis of the issue at hand, with one axis of the offered analogous situation, the listener instead may focus on -- and comment about -- every other dimension of the two things that are wildly different.
For some thinkers, all those other differences are easy to factor out -- of course they're different in those dimensions, and the wild variance only serves to highlight the similarity-in-one-dimension-of-interest. But for other fuzzier/holistic thinkers, every difference is a distraction to be considered separately, and the attempted analogy may harden them against your point.
Worst case is when some other aspect of the analogy so dominates listeners' thought (or can be cynically flipped against you to imply you've said something you didn't mean). This is why Nazi analogies can be so conversationally-derailing -- whatever one small comparison was being intended, the response is "how dare you call [Bush|Obama|Teachers' Unions|Evangelicals|Mall Santas|etc] Nazis!"
Of course, if you already agree with a speakers' point, the analogy makes sense and helps make the matter vivid.
But when a listener intuitively disagrees, the analogy can derail discussion. Even though in the spirit in which it was offered, it aligns one axis of the issue at hand, with one axis of the offered analogous situation, the listener instead may focus on -- and comment about -- every other dimension of the two things that are wildly different.
For some thinkers, all those other differences are easy to factor out -- of course they're different in those dimensions, and the wild variance only serves to highlight the similarity-in-one-dimension-of-interest. But for other fuzzier/holistic thinkers, every difference is a distraction to be considered separately, and the attempted analogy may harden them against your point.
Worst case is when some other aspect of the analogy so dominates listeners' thought (or can be cynically flipped against you to imply you've said something you didn't mean). This is why Nazi analogies can be so conversationally-derailing -- whatever one small comparison was being intended, the response is "how dare you call [Bush|Obama|Teachers' Unions|Evangelicals|Mall Santas|etc] Nazis!"