They don't expect it; they ask.
And I'm replying: No, [...]
Point was, you claimed that they just expect it of you. I'm pointing out that, no, actually, they don't. They ask for your help - they don't expect you to give it.
And, as I mentioned - at the gate, Zevlor fights with you - not any druids, despite it being the entrance to their grove that is being actively attacked. At the gate, Kannon dies attempting to man the defences - not any druid, despite it being their grove that is being actively attacked.
The supplies and provisions that the tielfings are working with, guarding and managing belong primarily to the Druids (this is shown in one of the ledgers you can read) - the tielings are actively doing work for them to earn their keep, even while under the threat of being evicted in Halsin's absence. Yes, they're also managing their own things in preparation for leaving, but they aren't acting solely for themselves.
The reality of the situation is that the Tieflings are so blisteringly "good-characterised" and the druids are so extremely cruel-hearted towards them that it stretches the writing to breaking point and defies true engagement... that's actually a complaint I've seen from others and I understand it.
There's a lot that doesn't make any sense about the whole set-up, and it's a failing in the writing that that's the case... it does make discussing the intricacies of the situation messy though, especially if we're trying to measure it against reality.
Well, I can sacrifice my life for random strangers, marching with 4 people into a Goblin camp and trying to take down their leaders. And yes, that is pretty stupid.
Once again, "Doing something that is right, purely because it is something that should be done, and you CAN do it," I.e. If the task is within your capabilities, and you're being asked to do it by others who need it, but for whom it is not within their capabilities.
If you aren't capable of removing the goblin issue in some way, that's one thing - and sure, attempting it when it's not within your capabilities would be pretty stupid and reckless... but that's not the scenario we're talking about here. We're talking about something that is within your capabilities.