I saw someone in general chat say the population limit was 75 before the picks started...don't remember if they said EW or GD.
We had some group members mention "Where the heck is everyone" as they ended up in a pick upon zoning. I don't agree that it's too high. Maybe it's too low.
Massive geography, not massive concentration of mobs (especially quest mobs). Respawn timer was reduced in beta to help combat that issue, but it's still somewhat present.