I worked Loss Prevention at a major theme park for three years. This is just my opinion, but putting liqueur (your costliest drinking option) at relatively unsupervised carts and pop-ups sounds like a nightmare to me.
Not only are you trusting employees that normally don't bar tend to pour correctly, but there is also potential issues with them serving/hooking up underage friends or cute guests.
Sure, you still have those last two items with beer/pre mixed, but the cost of those is much lower, and the ABV is a fraction of liquor.
To me, pulling in the hard stuff availability to you everyday locations is just a sign of wanting a little more control over it.