Why? Because nothing can overcome the relentless raping and dumping of the botnets, etc. All coins nearly die from it. Quark was no exception. But Quark has already been raped and dumped for months. Doge is new and has to go through this phase. This will drive the price of Doge down down and yes down.
Also Quark's distribution is different, nearly all of its coins have been minted, there can be no more raping and dumping. Doge follows the old distribution where it will be profitable to rape and dump for many years to come. This will limit the price of Doge for a long time.
+1 Very good comment