[somenameforme]

It's not just the ad hoc nature of the hypothesis itself, but also the subsequent ad hoc retrofits and fine tuning. With enough unconstrained fine tuning you can create a signal from noise, even when no signal exists. Take for instance the geocentric universe. Ptolemy's model was completely wrong in numerous ways beyond just assuming everything revolved around the Earth, but it was sufficient to make highly accurate predictions by excessively fine tuning the model to fit observations. And as new observations contradicted the model, all you needed to do was just add more epicycles to also make them fit.

Those retrofits (or the results they explained at least) were then were used as arguments in favor of the model, which is completely nonsensical and backwards. I think the most fundamental factor in good science is falsifiability. But if we just engage in and accept ad-hoc retrofits, then models become completely unfalsifiable. And at that point, what does science even mean?