I haven't had an issue with most of my other rides, besides the monorail. I set it to "don't block station" and give very short load/unload times, so the cars zip along. But the guests seem to be able to get into and out of the train, skyway, jeep tours etc. fairly promptly. I noticed with the second of my two monorail stations, though, that the guests sit for a while in the car and wait, even after it gets to the loading area. Even after they get out, the queued up guests don't embark before the car leaves. Then they start to complain how long they've been waiting. I had to extend the loading times AND turn off "don't block station" for that station (but not the "first" one, it seems to work okay with my usual settings). So now the guests get into the car after standing there with their virtual fingers up their virtual noses for something like thirty seconds, but the cars are piling up behind them at that station, and now there aren't cars coming into the first station quickly enough, so the guest line is growing there.
I have it set so it will go with any load, also, so they aren't waiting for the thing to fill. They are simply slow getting in.
Puzzling why the monorail would have longer minimum unloading and loading times than the other rides.