My take is this:
-If you're inbound (with a bomb, like a dutiful team member), then shoot anything red you want. They have the advantage of knowing where you're going, especially on final approach. This is usually when I begin my bean boy bob and weave.
-If you've loosed your bomb, either by following the spirit of the mission to drop towards hangars/carriers, or as some do, at the end of your own runway or somewhere in between, then give the reds a chance to move. How much you let them move is a little gray in my book. If I'm alone, I'll usually let you up. If I have a blue inbound, especially a noob, I'm more aggressive, as to give them the rare shot at scoring a well placed bomb, before blowing themselves up.
If you just want to be a bully and get off on spawn killing, that's you're own dysfunction. If you're on my team doing it, you'll get no support from me verbally or as a team member. I may even giggle when you do finally go down.