What about the rest of us chumps WITHOUT TCAS?? We may not fly at jet speeds, but fast enough to make visual acquisition difficult, especially in some atmospheric conditions (glare, haze etc).
Not to mention the very fact that the object you are going to collide with does not move in the windscreen and is therefore even more difficult to detect.
But the ARG know this.
Whilst I am at it, if VFR aircraft are going to mix it with IFR aircraft in Class E, why is not the monitoring of the relevant frequency MANADATORY for VFR aircraft?