It's the same for me as well.

[he takes a drink.] What I don't understand is why even bother if we're going to destroy Macha in the first place.

[for that to happen - they must want something very badly on their part, and they didn't get it. it's difficult to say this without giving details of their mission to garrus, and he'd rather not break gag rules, but all the same. it makes for a good discussion topic.]