O.K. now explain why it is ok to give away your position with a light that also gives them an aim point but not sound?
because you've had low-light CQB training and know how to effectively employ a WML without becoming a self-designating target.
otherwise- racking the slide lets the intruder know you're there, but offers YOU zero combative advantage. it doesn't put your sight on target, it doesn't allow you to verify SHOOT, it doesn't illuminate your target for target acquisition. all it does is give the intruder an advantage he didn't previously have- he may opt to run, but as likely as not, he'll use that information to engage you.
however, if you know how to move through a low-light CQB environment, you know how to isolate and limit your light signature. you shine the light briefly to clear a room, or not at all.. then when you're in a decent firing position, believe you have an engageable target covered, you shine and fire or shine and dont fire. but either way, you have eyes on, sights on, and he has neither at that moment.