I initially didn’t see why they cast someone that viewers would look at and see ‘Dad’…but now I think Blackbeard is meant to show what Hook will become if he does manage to return to his old life. Their fight/his stealing the JR, is maybe the catalyst that makes Hook realize you can’t go back, no matter how much you think you want to. Hence the casting of someone who looks so similar to Colin, dressed similarly, only rougher, meaner, more vicious. Hook is looking at BB and seeing his own future.
that is a good theory. who knows if later on we’ll find out about a family connection
Keeper of Hook and Emma's smoldering first kiss, a certain Pirate's sauciness, the Evil Queen's snarkiness, Grumpy's gruffness and a drop of true love to make it all go down smooth.