The X-men live in a universe where super science, and mind control are as common to them as going to the grocery store is for us. Anyone who can reach Xavier will make Logan's mind a plaything.
This is speculation, of course. It's not like the writers have been subtle about the mutant supremacy being a new thing to the X-men. What happened in the transition and why was that not shown?This thing of "off-panel" shouldn't be used as justification of bad characterization.
Logan is really old so he knos the worse and the best of humanity to talk about it
it shows that the writer doesn't care about characterizations