Sufyan: It wouldn't be much fun being a superhuman sneak expert if everything was "realistic" yet you are stuck in a cramped first person perspective with no peripheral vision. Loud and lit up cameras makes it so that you can plan your approach and overcome the limited control you have over your character and actually feel like a superhuman badass.
Most of the time, actual realism has absolutely no place in games. Representative realism on the other hand can greatly enhance the experience. JC Denton is expertly trained and has superhuman senses, he SHOULD be able to figure out standard security systems and circumvent them with ease. The player however would be severely handicapped by a visually realistic representation of security cameras (ie discrete and hard to spot). It is the same reason no games actually feature realistic injuries because just one bullet would render all human game heroes unable to continue their adventures even if they survive. Games can have representative realism in where getting shot can outright kill you or make a single battle difficult to win, but not make the rest of the game impossible to complete.
Cameras are not noisy and lit up in real life, but by making them so in the game you actually get a more realistic feeling game as the flow of the game (uninterrupted by quickloads) feels more believable, the experience of actually being JC Denton in that world is realistically represented. It effectively hides your not-so-superhuman control over your superhuman avatar from you, aiding the suspension of disbelief.
Well said.
Imagine if there was no save/load system.......