Here's a new rule for technical discussions: any time someone introduces a metaphor or analogy, it ends with them—that is, the analogy is only in play for the duration of the message where it is first introduced. If you engage the point being made by trying to build upon the analogy or recast it with some tweaks in order to make a counterpoint, then you automatically lose. (In a truth-seeking discussion, this amounts to forfeiting your attempt and being obligated to try again.) The game of "strain the analogy" is neither useful nor fun.