Recently I was browsing through stackoverflow searching for interesting questions and answers.
Question that raised my interest was:
"What you don't like in agile development?"
And the answer with the most votes started with: "I don't like seeing people focus on "what" and missing "why"."
You can have a look at the full thread here.
And actually asking "why" is one of the main attributes of the agile software development. But as hype was created around agile methodologies everybody are happy with the fast delivery and smaller number of bugs. And some agile teams had adapted to this style. They are developing everything that is thrown on them for the given iteration. Sometimes request does not give sense but it is implemented anyway.
But we should not forget that idea of the agile methodology is to help customer build better software. And we can build better software only if we ask customer "why?".
So next time when you meet strange requirement ask the customer "why?". And keep asking "why" as long as you don't get to the core of the problem. And don't expect that you will get easy to the core of the problem. But when you are at the core of the problem there is big probability that you will be able to propose better solution and thus help customer to build better software.
Don't forget that software development should be fun.