Credibility and Minutia
I actually think one should have practical know-how, and my reasoning is that I think it poses a problem in the realm of public perception. For example, let's say Joe is a professor of philosophy but he knows absolutely jack sh*it about how the pipes under his house get his water or something like that. He just hands money to a repairman when things go awry and away he goes back to working on his new book. Joe's neighbours might associate him with the stereotype of the academic who can write theory all day but doesn't know anything remotely practical. Joe is afraid to get his hands dirty, and he's just a sissy liberal arts major or what have you. This is a little different, but I think another example is Western self-help commodifications of Buddhism, Taoism, Stoicism, or whatever. All talk that was carefully researched by someone who knows what they're doing, but no show on how to actually do anything. Praxis and experience greatly increase a person's credibility, because I can know Kant from A-Z but where does that really get me?