The comment I replied to said "You really shouldn't try to use metaphors when making an argument." Was Shakespeare not using his characters to present an argument for dramatic effect?
Shakespeare is entertaining and metaphors are fun. Do you disagree with a poem and bring up logical fallacies? Of course not, we read them for entertainment value and anything we learn is a bonus. That is separate from metaphors used when trying to discuss the nuances of an argument within the confines of trying to have a logical argument. Poems and Shakespeare aren't supposed to be logical all the time, that would be boring.
Which logical argument are you referring to? Scott Hanselman used an analogy to make an observation about javascript. It's a blog post, not a rigorous mathematical thesis. Who are you to say what rhetorical devices someone should or should not use?