Well, the alpha borrowed textures, models, etc. from EQ as "placeholders" during development, along with a lot of EQ's source code, which became public domain after Verant Interactive closed its doors. Before ESO was publically announced, the project was even code-named "everquest" because they knew their project was to be a mmorpg cookie-cutter clone and a quick cash-in on the franchise's popularity.
EverQuest, originally launched in 1999, was one of the first MMORPGs to achieve great success and notoriety in the genre. Sony Online Entertainment's game has spawned a large number of successful expansion packs, continually adding to the world of Norrath and its history, races and classes, making EQ one of the most robust games available. In 2004, the game spun off a hugely successful sequel, EverQuest II.
Now lets see EverQuest was created by Sony, ESO is created by Besthoft and Zenamix Online (both different developers and companies) they don't even work together, Eso has its own made Game-Engine. Now all the things you said made no sense are not even relevant to ESO, can you please stop hating a game for no reason?
And ill ask this again when did you try out ESO? Because there is no such thing as a Alpha Leaked "thingy".