We have three major wooden coasters, all of which require lots of upkeep over the off-season. All of them run pretty well (Boss might not be the smoothest but I don't think any amount of track work could fix those godawful trains). That requires a large maintenance budget alone.
Yeah, it's annoying we haven't gotten a major coaster in awhile. But the bellyaching, "corporate-is-ignoring-us" comments are so tired at this point. There's like 4 parks in the chain that get new coasters regularly. Coasters also aren't the only investments parks need. I mean, we were in the first pair of parks to receive Justice League, which is more exciting to me than most of the recent Six Flags coasters. We are also receiving millions to renovate a carousel, which most parks would have discarded of by now.