i will attempt to argue semantics with you (note that if i succeed, this sentence is no longer correct, according to you).
webster says:
"to make an effort to do, accomplish, solve, or effect"
" ATTEMPT stresses the initiation or beginning of an effort <will attempt to photograph the rare bird>"
note that nowhere does it say "make an effort to do, but fail". i do not think failure is implied. if you succeed in climbing a route, does mean you never attempted it?