Their point, applied to that situation, would be that if someone does argue for enforcing TPM-backed measured boot yadda yadda to address scamming, trying to counter it by dismissing scamming as not a real problem is useless.

Scamming is a real problem, but that does not imply this solution is the right way to go about it. There are other means to address this problem; they may not scale as well, but they also don't sacrifice computing freedoms.

I get it dude, but my wider point is that we need to question where this line of argumentation leads to.

Are we saying that, because scamming exists and we haven’t proposed an alternative, it means that clamping down on software installation methods is a legitimate solution to the problem?