Why does this Bayesian regression analysis fail?

Mmmh, would you have simply done this, in order to check? (see image below)

az.plot_ppc(idata, group = “prior”, figsize = None)
plt.show()

What would you have concluded? And what steps would you have taken? Just spontaneously re-scale the data? Or modify prior or something else?

I ask these questions because I am really very interested to know how someone who is used to PyMC would have reacted, faced with such data…