This makes more sense when you remember that being "concerned with reality" for a salesperson mostly means "Getting the commission paid and moving to a different role before everything blows up too badly", rather than "delivering software that meets the sales deal's contractual requirements".
Salespeople are too rarely judged/punished for the disastrus messes they leave behind, and all too quickly judged/rewarded for being able to convince a customer to sign off on a big number without any care for long term implications of that deal...
Or as one VC put it: Never let facts get in the way of a good story.