I think you're absolutely right about not wanting to bog down your salespeople with old relationships. Here's why:
It seems to me that a lot of companies who are at the point where they'd hire a full-time sales staff struggle with their early clients and not-quite-clients. In hiring salespeople, companies are defining themselves as established players with an established product to sell, whereas the relationships with early customers centered much more around being the new guys on whom the buying company is taking a risk and often getting a say in feature development and a discount compared to the competition.
Re-framing those early relationships, especially "with middle managers from dinosaur companies," is a very long and frustrating process for all the parties involved.
I could absolutely see why you'd want to avoid your news sales staff getting sucked into those relationships and instead do what they're fantastic at: parachuting in, developing new relationships quickly, and pivoting those to closed deals.
(Background/assumptions: I do bizdev-ish things for a large tech company. From the tone of the article, I'm assuming that we're talking about B2B businesses with products priced such that the relationship with individual clients takes time to develop.)