Come on, don't bash EQ, it's still more open world than ESO.
ES games are not sand boxes, they're open world. Just like EQ. ESO is linear PvP centric game, it's about as far from open world as you could get.
EQ was successful because UO catered to hard core PvPers, EQ catered to hardvore PvEers, they went after different markets.
ESOs caters to the same market every other mmo released in the last 10 years do. Which is to solo casuals and pvpers.