Mid air is my greatest flying fear, anything that says 'Hey I'm here!!!!' has got to be good.
We fear it because we can envisage getting into a situation where we contemplate our inevitable fate for 60 seconds without being able to do anything about it. We're pilots, and fear losing control. However en-route, mid-air collisions are pretty low on the list of things we should fear. Not saying we should ignore the possibility, but issues such as inadvertent VFR into IMC are statistically much greater problems. Flying is about concentrating on the right issues to the right extent, so any action - particularly one imposed on other people - ought to be proportionate. For example, on another site someone was ranting about BASE wingsuiters and the risk they posed to light aircraft.