In December I think they landed it on land. It all has to do with the entry back from space where.
I found this
Some say that the barge would be much farther from the launch site and would allow the first stage to follow a mostly unpowered ballistic trajectory with some correction. However, it doesn't -- it has a boostback burn. This is because ultimately SpaceX wants to RTLS. Thus, they want to test a full, reversing boostback burn -- but can't for safety reasons. The difference between this partial reversing burn and a full burn are, relative to the entire first stage prop budget, small.
Still not sure but safety would be a concern with it falling on populated area.