Okay so clearly hiring people just like you is probably not a good idea, not just because the qualities that led you to be a founder are likely present in the prospective employee but also because you're likely to suffer from confirmation bias if you hire someone that thinks in a similar manner to yourself. However, that said, this article does a horrible job of prescribing an adequate solution to hiring practices: personality tests? Are you kidding? Easily foiled, especially when you understand its purpose, i.e. to assess whether you work well with others. Someone in need of a job is probably able to not only trick the testers but also themselves into believing they have the qualities necessary to get along in the work environment. A better solution might be temporary work that has the possibility of becoming full-time. While this isn't always possible, it should be possible to at least ask for and follow up on references for any perspective employee.
You're right, the article is sort of clumsy. There are three sparkplug issues at work here: 1) founder self-awareness 2) how to hire people and 3) how to develop effective teams. They're all lumped together in the article (and in many actual companies). What would have prevented the problem in the first place? Somehow short-circuiting the tendency, especially in founders, to insist the same qualities as your own are most useful in business building.