You guys would likely be alright with the trade if you were a legit contender, but the Mets are not that. SWR is a fine pitcher but the likelihood that he ends up being as good as Stroman is about 10%. The probability of him becoming an ace is pretty small.
It's a weird trade for the Mets to make so I totally get why Mets fans are upset, but it was still poor value for what Stroman is. Really, a lose-lose for both teams.