You claimed without evidence, or more accurately, bad evidence, confusing RTOS with "reliability and security." And you were somehow confused that security mattered for systems with no network connection.
FYI: For most commercial network equipment (internet backbone and similar), reliability and security are the highest priority. Most of that is Linux, BSD, and friends.
FYI: For most commercial network equipment (internet backbone and similar), reliability and security are the highest priority. Most of that is Linux, BSD, and friends.