Syndergaard being good, I still wouldn't label as a "great concern". An arm is an arm is an arm, and an arm in A ball would be hard pressed by statistical likelihood to ever topple the balance of a trade for an MLB pitcher that was as dominant as Dickey in 2012.
But when JPA is your starting C in front of arguably the best catching prospect in the game, and you choose to trade said prospect for a 38 year old pitcher, well... that is and likely always will be the gist of the swap. Getting Thole is certainly a point, but it's a small factor when viewing the thing in totality. There's no need for us to be so myopic, just because Toronto was.