It is not the fact acts don't want to come to the Palladium; the park is just not willing to spend the money to book them. Artist are paid a certain rate to play venues, and it is up to the promoter/park to make their money back. Cedar Fair could book acts and cycle them through all their parks if they cared to do so.
This is not the way booking major touring artists works. While Dani did tell me a couple years ago that Management (then) had no real interest in booking touring recording artists (due to the market's saturation), and would only focus on what they have been the last few years (Christian concerts, etc.), when it comes to booking touring artists, it has nothing to due with the park spending money or not.
When an artist or band goes on tour, they usually go thru someone like LiveNation (who owns a large number of venues) and, in cooperation with companies like TicketMaster (who has rights to many other venues), they map out where they're going, contact the venues to book, and pay the venues. Cedar Fair owns the Palladium. Now, the concert promoter may come to them, and in the Scotty Mcreery case, they obviously did, but in a city with 2 other newer, more popular amphitheaters, as well as an arena, stadium, and various theaters and small concert venues of different size, who hold events constantly, theres not really a reason to book at Carowinds all of the time in this day and age.
Six Flags occasionally has a small summer concert series where they have usually free or low cost concerts of Z level pop artists at their smaller venues, mostly amphitheaters that used to hose the Batman Stunt Shows, and it's very possible that Six Flags paid them to come there, but that's a very different situation. Couple hundred people at best, and the park caters to a very young crowd with those concerts, which they use as a promotion during the week to get more people into the park.
The Palladium holds 13,000 people. It's not a small venue. It would be very costly to tear out. And there are plenty of things it could host. I'm sure that a former Disney Exec can figure out what to do with it.