Yeah, but if the land is *most(ly)* impressive at night, that's problem -- either it's bad design, bad concept, or bad planning. If the design requires darkness for the effects to work, then simulate darkness (i.e. Pirates, Knockturn, etc.).
Not to mention, most guests (those of the "I'm just here with family on vacation" variety) won't know that they need to see it at night.
But, yeah, a lot of tourists and locals like seasonal Christmas lights. That's true.