The parent said it was a sign, not a certainty. If it is a stereotype, it is not an ignorant one.
I feel "professional" managers are bad for tech companies. Here are two reasons :
1. A lot of management techniques that are taught in business schools apply to traditional manufacturing based businesses. A lot of these underlying assumptions are invalid in the tech businesses.
2. Tech businesses require a deep understanding of what is possible with the current state of the art. This is requires a deep understanding of technology so that when there are fundamental changes to the landscape (which happens more frequently in tech) the company can adapt and stay relevant.