One major problem with Six Flags is that most of their parks, except for Knotts, sold out to the coaster craze and became primarily 'coaster parks'. Well, that worked for a while. But now the demographics have changed, and the Six Flags/Cedar Fair prime customers, teenagers and twenty somethings, are a declining demographic since family sizes started shrinking two decades ago, and have accelerated the shrink even more so now.
I remember when parks like Cedar Point, Paramount Kings in Cinn. before Cedar Fair, and even the competition's Sea World BGW were more balanced parks with lots of entertainment and non coaster attractions that would attract a larger, and older, demographic in addition to the youth..
Balance in parks is a plus. But the coaster parks got rid of the non coaster and entertainment attractions and became one dimensional. Now they pay
the piper. Their prime demographic doesn't have spending assets or spending power. The parks can only squeeze so much out of their bare wallets.
Heck, SF financial situation is so poor that they even have difficulty building unthemed new coasters, let alone a real theme park (Disney/Universal)
ride. Herschend has done better. Their parks remain balanced and I'm guessing that they might end up acquiring a couple of the best Six Flags parks.
They already bought Kennywood, though not really a regional park, but has always maintained a balanced attraction line up. A good buy there.