It doesnt make sense to us because it seems like a pretty good deal from our point of view but Chuck said he is not looking to play the pass line, he is looking for the BIG score.
Revenge on Captain Hadley is the big score.
Plus I figure he was not
guaranteed a return to normal by Wendy if he helped her and he may still have an angle to help her later
And his pops will survive for now
And pops and Wend were tag teaming him earlier so he might be feeling like
"these jokers can wait"
, not even counting that Grampy Pancakes gave his grandson a slinky as a birthday gift.