Your quoted text actually justifies Amelius' assertion: the functional category is the same, but the implementation differs, and the judgement (and the law) hin

Your quoted text actually justifies Amelius' assertion: the functional category is the same, but the implementation differs, and the judgement (and the law) hinges on implementation. All this means is that the definition of taximeter (as a single-purpose device) is now outdated. It's actually a pretty bad example of the law adjusting to new technologies. Just because we like the outcome doesn't mean we have to like the way it happened.