Perhaps so. It doesn't sound like a case of ruling out one thing ruling in another, not when we still await direct evidence of dark matter.

Maybe not centuries given the rate at which things occur today (though the first team to detect a neutrino only got a Nobel Prize for it a half century later). Blind alleys and group think remain a valid concern though, one that's more serious rather than less as theories advance. Dusting off terms like "quintessence" for dark energy doesn't exactly reassure me there. Bottomline is that any time people become so committed to a theory that they cease questioning whether it could have a fundamental flaw all the review and experimentation in the world won't help them; when the evidence conflicts with an inviolable principle the search begins, not for a more accurate principle, but for a way to reconcile the evidence with the flawed the theory. That process will last as long as a community is willing to pursue it, and is less a function of research than of the theorys social inertia. If you say that's not happening I'll accept that since you're obviously in a better position to say so, but modern science hasn't made it impossible, and the idea it has is another example of the kind of unassailable certainty that makes me nervous.

Interesting comment; do you think someone has a FULL understanding of the situation and evidence, or that all proposed solutions are futile?