It's just a tedious game.
Once the pin is set up and the other guy's deck is dead, just buy one copper per turn.
Or, you can stop the pin when there are 3 coppers left - you play TR,TR, Outpost,Masq, buy a copper, use the outpost turn to buy a copper, your opponent buys a copper, then on your turn you play masq to give him a throne room and take his copper. And bam, you have three coppers in your deck, enough to buy a silver, and thus enough to get an economy started, whereas the opponent can't get enough coppers. Faster than emptying out three piles while keeping the pin going.