I am no expert on stainless steel, but from what I know there are different grades of stainless steel, and many of them work harden, due to heat and/or "work". It could be that as some types harden they might also become brittle and fracture, whereas high tensile bolts tend to remain more stable re hardness and mechanical properties.
That said, I always thought that stainless steel were good for such use as mentioned, unless authenticity was required!