Biases, "respectable" economists and their policies
Imagine you see someone using a frying pan to put nails in the wall. You tell them, "No proper homeowner would do that."
While using a hammer is correct, this way of speaking doesn't persuade. If their method works for the few nails they need and nothing seems to go wrong, just saying it's not 'proper' gives them no real reason to change. You miss the chance to explain the actual advantages of a hammer that matter to everyone – maybe it's faster, safer in the long run, or avoids hidden damage. These are better reasons than just talking about being 'proper'.
We see this same problem often when people discuss economics. When important economists say, "No respectable economist would support these policies," it's like the frying pan comment. This kind of statement often doesn't reach the people it's aimed at. Why? Because the people who do support those policies probably don't care about that particular group's idea of 'respectable'. So, the criticism becomes meaningless noise to them. This approach builds walls between groups (echo chambers) instead of helping understanding or allowing challenges to possibly bad policies. It stops people with different ideas from talking to each other, which is necessary to check our own biases (see confirmation bias).
Instead of focusing arguments on what 'respectable' experts approve, perhaps the real challenge should be looking for ideas or criticisms so fundamental, based on clear evidence or logic, that even economists with very different or less 'respected' views would have to agree they are valid, or at least seriously discuss them. Finding this common ground, or points of disagreement that everyone acknowledges, seems far more productive than relying on the label of 'respectability', which is often subjective and used to exclude people.