You're complaining about only two trains at a time? That's 32 people, which is pretty standard for a RC. And to their credit, the Mummy staff is pretty good about dispatches. Most of the time if there is a delay, it's because of a guest (they have a loose item, don't fit in the restraint, etc.)
But yeah, given all the rumors of it going in the near future, it seems odd to paint the roof unless it was sticking around longer than we thought. To be honest, while I admit it's not a great ride and we could use something better, i do still find it enjoyable for what it is.