Because underwriter stage is the last stage before mortgage offer. I remember my MA telling me that they operate at their own pace, can't be chased ( I was trying to chase it up), but they do eventually come through and that should be it in terms of the decision.
Which would be fine were it not for the fact that the MA said we had already passed the underwriter stage last week and is now saying it's not for another 2 'stages'.
Honestly not sure how you're drawing that conclusion (that they'll come through) but I like the optimism nonetheless.