5 coasters in 90 mins = 18 mins per coaster. Assuming you rode each once, and taking into account the walk between coasters and each ride's cycle time and I estimate you couldn't have waited more than an average of 15 minutes for each. If that's the case it sounds like crowds were light, in which case a 1-train op was probably sufficient.
So how, exactly, were operations horrible in that respect? On most summer days waiting 15 mins for a coaster would be a dream scenario.
If I were you, I would be glad that the wait was not longer for them and that you got on as many as you did instead of complaining about a 25 minute wait at the end of a summer day when ride ops are tired and energy is running low.