I don't think this is true. Demand and Agglomeration effects will always increase land/location value. The question is whether or not there is an increase in land value per capita. When you limit density then only those most willing and able to bid up the price of locations will increase the land value per capita. If you allow density the land value per capita will decrease (more affordable) while the total land value still increases.

Edit: Any perceived amenity affect from limiting population density is really just a scarcity effect.