User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-25186657-20141201230343/@comment-3046679-20141202131719

I've explained Shay's motivation at least three times on this blog, and not gonna bother doing it again. You bother to search previous pages, unless you're willing to remain ignorant.

It's not a perfect motivation, but it gets the story going. I'll even go as far as to say if we had Shay in AC3 instead of Connor, that alone would make it better, since he's a much better character.