My point here is not to defend MMT but the quality of the conversation.

If someone comes along and says Modern Moo-netary Theory says we should to build too many catapults, and another someone points out that the theory doesn't address questions of "should", pointing out that the theory talks about spherical cows in space doesn't rescue the original objection.

That a theory makes unrealistic assumptions is absolutely an appropriate objection to raise, but it belongs upthread. Otherwise it won't be seen by people who've already decided what they think of the narrower topic of this subthread, and we'll get more repetition of worse arguments.

My objection is to people talking past each other rather than engaging (whether intentionally or unintentionally) and remains as relevant as ever.