> They might have artifacts. Don't underestimate this one; unless you're playing on a huge map, you need every chance you can get.
> With Entrenchment, you can now put a starbase around them. That can mean trade ports and colony pods, in addition to the tactical bonuses. Very expensive to do this, though.
> It's nice to have a front-line system where you know that if the planet gets bombarded half to death by raiders, it won't cost you much to rebuild. Watching a 300-pop planet repopulate from near-zero, with the resulting loss of income, is painful.
> With 25 tactical points, back-line dead asteroids make great places for placing more superweapons.
> For a Vasari, it's another phase gate location. The starbase phase stabilizer just isn't nearly as useful. And asteroids (dead or not) make GREAT Vasari fleet bases, as their gravity wells are small; it's far easier to get across them if you need to quickly jump to another planet to respond to an invasion. TEC and Advent want to defend the high-value planets first, but for a Vasari, those big wells are just too easy to get bogged down in.
> If you don't take them, the enemy will. Giving a Vasari enemy a forward base for a stabilizer is just asking for trouble.
> There are no AI defenses on them at the start of the game, so why NOT take them if your colony ship has a spare minute? It'll only cost you a 450-credit upgrade to keep them from costing you money.
Now, given the choice I'd take a regular asteroid over a dead one any day, so I rarely bother adding these on a custom map. Personally, I think they (and pirate bases) should have been bumped up to 35 tactical slots to compensate for the loss of the twelve logistic slots.