Not following you. In any frame, the shock is the travel limiter. If you take the shock out, the rear triangle crashes into the front triangle. Unless you're referring to other frames having a seat stay bridge that crashes into the seat tube before the tire does?
Doesn't seem like this failure has to do with overtravel. The seat stay just isn't strong enough to handle the bending forces put into that big cantilever at full bottom out. Not a fan of that design in general, even if it was strong enough. Often times the shock rear pivot is mounted to the upper link. By having the seat stay be rigid all the way from the rear wheel up to the shock puts a ton of bending into it.
