Why is hiring for sales so difficult?

Why is hiring for sales so difficult? Controversial opinion here: sales people have sweet spots that even they might not be aware of.

It's one of the things that makes hiring a salesperson so darn hard. I think your needs and their experience need to align on the following:

❎ Product or service offering
❎ Price point of the sale
❎ Relationship or transactional
❎ Industry
❎ Outreach or account management

In the consulting that I do, I'm often brought into a small firm after a biz dev person has failed. Making the transition from founder-led sales to sales led by anyone else is one of the hardest parts of owning an agency- and I think this represents a big part of the problem.

Agree? Disagree? Biz Dev folks- what's your sweet spot?