That doesn't matter when you can only be shot at during that same small window (if even that)
MCF - you can't be saved from your misconceptions, so I'll just note your comment is a gross exaggeration, we agree to disagree, and save everyone from 20 posts.
Frosty - If I'm in ASF, I spend my entire game in ASF doing one of two things: 1. anti-air and CAS ASF (LBX or ATM), or 2. TBolt/FBomb/LBX hitting where my team is fighting, base-taking, or where they are taking fire from. I can't speak for everyone that flies, but there is a good reason I'm usually below 600m rather than above it. All, of course, with varying degrees of success depending on the opps, map, and the situation. I don't need to type anything to see where the action is or have situational awareness (like killing BA with LBX or AC or missile strafe on or around friendly mechs, for instance, which I do all the time).