In the time frame they are talking about, 1993-1994, almost nobody was using Linux commercially (except tjhe distros selling it). Even after that, Linux was fairly immature. If BSD was going to be a real contender, it still had a sizable lead. That it didn't win in the end leads me to believe other factors were more important, such as the license (which the article you linked also notes).
The BSD license is more permissive and appealing to a lot of organizations, but the requirement of the GPL to give back ultimately lead to a virtuous cycle where companies moved portions of their code in-kernel, because out of kernel is more problematic if it's also not proprietary.