SNS, I think we might be separated by a common language here because this discussion seems to be going round in circles and I think we are mainly singing the same song.
I've seen people fall victim to the tendency to let the TCAS spot traffic for them.
In what capacity have you seen people 'fall vicitim'? I initially got the impression that you are an airline pilot; your profile doesn't mention in what capacity you operate or what licence you hold.
I have seen some pilots over-concentrate on spotting a TCAS 'target' that will not conflict, almost as if they try to prove to themselves how good their eyesight is. Meanwhile, they neglect the rest of the sky. Is this what you allude to? If so, I agree but this is a training issue, not a fault of the equipment. Just like over-concentrating on anything else inside the cockpit or getting distracted.
I've been flying TCAS 1 / TAS equipped aircraft for almost a decade, most of it outside controlled airspace, both single pilot and multi crew. I previously flew more than twenty years before that without it. All the instruction manuals I've read have stressed that avoiding action must NOT be taken on TCAS / TAS derived information alone, it is an aid to aquiring visual contact, no more. I repeat, TCAS must be used properly, it's a simple tool or aid to be used as part of a lookout scan, definitely not to be used as a replacement for lookout.
Every pilot I've met has been intelligent enough to realise that the equipment is far from infallible; i.e. if other aircraft aren't squawking they don't appear on TCAS. Similarly, an ATC service can only do so much, especially outside CAS. Some aircraft present a poor radar return and a controller may sometimes not be in a position to pass on timely advice on a 'late spot'.
Having said that, I would NEVER turn off something that might just save my neck and that of my passengers. I might turn down the audio warnings as low as they go via my headset control but would never turn off the box itself. A TCAS screen full of diamonds is not a distraction; it just reminds me to keep looking out of the windows.