I dislike fights on top of the volcano with a passion because that LOS over the lip makes healing impossible. It's also constantly pelted with exploding rocks, which doesn't help matters. Lastly, it's as easy as pie to get KB'd off the top of it (most other areas there's places you can stand to mitigate your chance of ending up in lava).
Fully agree with retreating (or not, as the case may be). It's a losing tactic, and one that should only be resorted to when you're already on the back foot. Momentum is everything in TA (could say the same for any zerg type scenario), more often than not if you are the side advancing on the other side, you will be scoring more kills than they are. Reasons being, it's hard as hell (nigh impossible) to dps when you're running away, and it's slightly less hard but still difficult, to heal whilst running away. It's difficult to regroup when you have reached your muster point (people tend to just keep running).
I do not think that people realise that possession of the bauble in itself does not score you points (in any great number at least, I do not think it awards any), and this is the issue which causes people to play the game incorrectly.
Much better in my opinion to go on the offense when you have the bauble. Posessing it means that you score more for enemy kills for the duration, so why not capitalise on that. Let's face it, you're going to lose the damn thing sooner or later, and there's a good chance the enemy side will snatch it. If you look at it like that, you have a limited time holding the bauble, therefore it's infinitely better for your if you have been rolling them to the best of your ability, rather than legging it back to your half during which time you're not scoring kills. Keeping the enemy dead also increases the chance of retaining possession of the bauble, letting them zerg you in your base is just asking for trouble.
It's also a pussy thing to do.