Who has people that travel on business and dont know this?
A fairly typical business trip hotel, its my room from last night.
Look at that door. No spy hole and no secondary lock. Anyone with room access has access to your room.
In a typical hotel, housekeeping, security, maintenance and possibly a number of others have access to your room. Couple that with people with serious intent and that is car too big a risk.
In this case a doorjammer or doorstop wedge could be used to significantly increase your personal security.