Back when I played this game to death in the mid nineties on my old Macintosh, I always encountered this issue; I could have a well established park with hundreds of punters coming into it each month, making me a load of cash with all the amenities, drinks stands, fast food, mechanics galore keeping on top of things, handymen everywhere keeping the place clean etc. As soon as I built something like a seventh ride in the park though, no matter what it was, everyone would up and leave. After that I'd maybe get a handful of peeps coming in on the bus but unless I removed that last ride I built to bring the number back down to six, I'd never see huge throngs of punters again.

I've often wondered if this was intended gameplay, and perhaps my park rating wasn't ever good enough to "support" more than six rides, or if it was just a bug.

Edit: For the sake of following this up in case one day someone actually cares and comes across this; It was a bug in the Mac version apparently, and not the only one either. All these years later I've finally got a chance to play the original PC CD-ROM version of the game and this issue I talk of doesn't occur, among a few other minor things, plus the sound quality is also noticeably better in the PC version too. So that settles that. It's only taken me 24 years to figure it out.

I still have the 30plus floppy discs that I used to install this when I was no more than 10 years old and I am loving the gog version because as you said, there seems to be less bugs than I remember

Although I have just hit a bug on my new Zealand park where the steakhouse,balloon world, 1 of 2 toy worlds and 1 of 2 coffee houses have just stopped selling and when you hover over them the icon overlay for placing a new shop appears, slightly offset from the existing shop, its really weird....

Even more strange is that my whole park is full of baloon holding guests but my only balloon world has only sold 26 then no more sales...

The GOG Version is the CD Version , which still has as many bugs as I remember.
Prominently the missing Icon for the Security Guards.
There are far more worse bugs though...

I still hope one day someone might pick the source code up and do a us a big favor and fix these bugs. Don't know how it was released by EA anyway back than. It was stable to a certain point... oh well they pulled this through till today.

Can’t say I’ve ever noticed that one with the Balloon World, Steak House etc. though. Suppose you could try just removing them and rebuilding them? Unless it won’t let you of course. Almost sounds like the game already thinks they don’t exist hence the weirdness with the overlay. Alas though I don’t think we’ll ever see an improved engine for this game or even a proper spiritual successor. I always thought it was quite popular which would warrant both, but apparently not. Other games in Bullfrog’s inventory seem to always get the limelight, mainly Theme Hospital, of which there’s been an open source engine replacement and even a spiritual successor in the form of Two Point Hospital (as well as a few other crap attempts over the years). Theme Park continues to get left out in the cold it seems.

I mean yea, it did technically get two sequels (both were a bit shit though, I remember playing Theme Park World and I didn’t like how they took the game's name literally and made it so you had "themed" parks (like Horror/Jungle and so on) and also got rid of the business aspects. Then they made Theme Park Inc. which was the same as World to the best of my knowledge but did include the business stuff, but I think it came along too late for anyone to care (I didn't even know it existed until much later in fact).

Meanwhile there’s been a bunch of similar games over the years but it seems like Rollercoaster Tycoon and it’s sequels were considered the better games by many to begin with and so they’ve had all the love over the years as well as spiritual successors while everyone just forgot about TP.

Oh well. At least we can still play the original, even if it is a bit of a mess by today’s standards.