It's simple maths really... 360 million DOGEs are issued daily. At 110 satoshi, 400 BTCs are needed every day to buy the mining supply, just to keep the price stable. At some point, the inflation numbers eat up the BTCs, the BTC investors dry up and the game is over => the only way is down.

When you know that in a year from now, there'll be almost double the DOGEs, and bitcoins will be more-or-less tha same in numbers, it's a no brainer why the Doge/BTC price ratio will go down and down and down.