I clearly failed with the post (by not elaborating) on this point - I never meant forcing fake data where it's not possible. I'd still rather have this conversation:

A: We should definitely do X!

B: Why? Why not Y?

A: Because I'm the authority in the room

B: Well we talked to sales and customers and Y clearly has Z impact, on the other hand we saw no evidence of customers needing X.

than

A: We should definitely do X!

B: Why? Why not Y?

A: Because I'm the authority in the room

B: Whelp, ok I guess