It is not great advice. This early on, there is a big difference between someone who comes on as employee #1 vs a co-founder especially in terms of ownership, but not a big difference in terms of risk exposure. If you are positive you've found product market fit, hire a sales person but don't be surprised when the sales person can't sell due to a number of product problems. I would not expect that person to own the product in the same way as a co-founder unless you treat him as such.

Parent comment places way too much premium on equity at a time when equity is worthless.