A lot of people forget we had very little budget left (something like $5M +/-), so they got the best pitcher they could within their budget constraints. To get a Cy Young winner making $5M a year was a pretty solid coup when you're pushing all your chips in and saying it's time to win now.
http://www.baseballamerica.com/today/prospects/rankings/top-100-prospects/2012/2612998.html
Take a look at the top prospects list in 2012. (If they were in our farm system) we could have traded Julio Teheran and Jesus Montero - the 5th and 6th top prospects in baseball for Dickey and we'd be considering it a "win" right now. Thor could have turned into Matt Moore, Shelby Miller, Trevor Bauer, Dylan Bundy, Tyler Skaggs, Danny Hultzen, Jacob Turner, Mike Montgomery, Jarrod Parker, etc....all of whom were as sought after as Thor at the time of the trade....and nobody would still be talking about this trade (although it looks like Moore may still turn out to be a stud).
There is a considerable amount of luck involved in making trades. No need to continue harping on it (although it sucks donkey cock that Thor isn't in a Jays uni).