No, it makes less than 0 sense. So you are saying from an RP perspective it makes more sense that a mob should ignore a guy standing 20m away from him pointing an assault cannon at him and attack the guy in stealth standing 25m away and not looking at him. Because that's what happens and what the real issue is. I used to spend alot of time running around with a friend who played a scrapper and it happened all the time where they were stealthed, I wasn't, I was closer to the mob than they were and it would aggro on them and pop them out of stealth. We spent some time experimenting with it to confirm it and there are several mobs in this game that have an aggro radius of approx 20m for normal chars and 25m+ for stealthed chars. Happens on Ilum especially for solo content and in most HM FPs and Ops as well, which puts Scoundrel and Ops DPS at a significant disadvantage due to their lack of a gap closer, which is what stealth is supposed to give them, but doesn't because of this.
Yes, it makes sense. This "feature" is used in many stories, book, movies or animes. The characters can sense the ennemy before seeing him. Against some ennemies, being stealth is like waving a big sign with big lights saying "EH, I'M HERE".
But I'll give you a wonderful example, from books/movies : when Frodo uses the Ring, Sauron (and any Nazgul) EXACTLY knows where Frodo is. When he doesn't, they barely see him in front of them. If you ask for more examples, I'll be happy to produce them