Interesting contrast.
1- A thief is hurt by a booby trap during a break and enter, then when the homeowner gets charged with something like reckless endangerment people say "but he was a thief!!!"
2- A biker trespasses and finds a possibly lethal trap in his way, then when no suspect can be found and the cops warn against trespassing, people say "but my safety!!!"
Morally I have no problems with traps designed to strongly discourage behaviour (eg bear spray, dye spray, room that locks and calls 911 etc.). When traps start killing people, that grossly exceeds the negative impact caused by their actions (thief or trespasser).
I have no problem with the rider being charged with trespassing if that is appropriate (private property, signage etc) but they shouldn't be seriously physically harmed for what is essentially a property crime.