[[No spoilers if possible as I'm reading it currently. I'm up to Jake's time in Derry now.]]

It seems to me that Al basically said "Jake, here's a weird time hole. Do you want to save JFK because insert random musings and Jake just went "Fuck it, why not?"

Like, is it ever adequately explained? Taking a risk that things would be better if they prevented the assassination attempt seems like lunacy.