Back in the day, PC's would get strongholds and followers when they hit a certain level. Every crap DM (myself included) would think is was a great idea for monsters to sack one while the PC was away. It was never any fun.
When a player puts a little effort work into something, like a castle, house, or cart, don't trash it without their buyin. It's like a thief stealing their items when they were sleeping.
There are better ways to use these new settings in the campaign.
Nah, this isn't comparable to stealing something while the PCs are sleeping or sacking a stronghold offscreen. The OP's example clearly has the player there so they had agency to do something here, but failed to save it. It's never your stronghold until you've successfully defended it.
The example in the op says nothing about whether it was ever possible to diffuse the bombs in the first place, so it's unclear if there is any element of agency at all, let alone how difficult the scenario is to win if that's even feasible.
Eh, I'd definitely say it's not a "don't ever do this" scenario.
For player agency matters- if luck had been on our side (if I'd rolled a longer fuse, if we'd coordinated better, if I'd gone down instead of up first) then yeah, we could have diffused them.
Regardless, I think it works for the story. First off, it's something I gave myself in my backstory, not something I earned in-game. Secondly, I acknowledged that having this bar to defend was reducing my character's desire to go after the main story line (so I shouldn't have been surprised ;) ). Third, this is intended as a short campaign so I think bigger character's-life-changing events are reasonable if not even expected. And most importantly of course, I trust my DM to make a good story, and he trusts me to help move the story forward in interesting ways. (despite what I said about defending the bar, I can find character reasons to move forward if I need to and have in the past.)
I freaking love Apocalypse World. It's one of my favorite systems by far. The world has so much potential to be as expansive as you'd like, and can fluidly adjust to the players actions. I've been running a game for a while (which is currently on hiatus because I have a new baby), and it's a blast.