It is not that rare that a very dangerous ATC clearance is in place. In my case, 3 times in 40 years of flight.
Crews have no business accepting clearances without at least an appropriate degree of safety confidence.
Crews might think that during radar vectors on a familiar route in day VMC and all good english speaking crews might not need the same type of situation awareness as more demanding circumstances. There is more risk with the latter, but I could have been just as dead with one instance of the former.
Some of us have been distressed to learn of the loss of a friend due CFIT. Avoiding CFIT starts a long time before take-off. Maintain SOPs, crew management, sober and rested and study unfamiliar routes will all help. Then when that slightly suspect ATC clearance appears, crews will be less diverted by narrow perceptions and lack of preparation. Just "being carefull" is not enough.