Simon Sinek and Peter Senge nailed it when they articulated why knowing "why" is critical.
Except that while "why" is critical to know, it's not the question to ask. "What" is much better.
Michael Bungay Stainer pins this insight directly to the concept of effective coaching but I think it applies more generally.
Even if you want to know why, or want to clarify why, or want to find out the options for why, taking a closer/harder look at what is probably the best place to start.
Imagine how this works in your context. You might be in a meeting, having a quiet drink with a mate, in the midst of a high-level strategy discussion, or pondering life while walking through a park.
In that context, you could ask one of these questions:
Why am I doing this?
OR
What am I hoping to achieve?
Why are we talking about this?
OR
What is behind this issue?
Why are we in business?
OR
What are we good at?
Why is this a problem?
OR
What is the main challenge here for me?
It isn't that the what question is going to take you to a different place than the why version. It's that there's more wiggle room for not getting someone's back up because you didn't quite nail the tone of voice, and also you actually take the conversation forward.
Do try it.
*The concept and inspiration for this post is directly taken from The Coaching Habit book. You should get a copy. If you're specifically interested in the relative strength of asking what versus asking why, it's covered in the "Masterclass 4" section of the book.