Well, your buying power was pretty weak, overall.. you did a lot of trashing of Coppers, and very little gaining of treasure. You had an effective $17 in the deck at the end (with zero Gold, and that assumes Merchant Ship, Black Market, and Trade Route don't ever collide), with only around 4-5 hand-increasing draws (depending on luck with Menagerie) each cycle (~4 turns). Also, why grab both Salvager and Upgrade when your opponent has already done the work of upgrading Trade Route turns 1 and 2?
But yeah, as Titandrake mentioned, there's a lot of luck involved, too.. I've had some 100% BM games that have managed to grab 4 Provinces by turn 12.. the odds of that are terrible.. but it happens.