Knowing common knots is not just useful because they are handy, but they also represent a common toolkit - when sailing with someone, if I see they tie a certain thing with a specific knot, I can do likewise. When I see a knot I recognise, I immediately know how to untie and re-tie it.

Generally the same point about having a common vocabulary in tech work. Sometimes it's about stuff that's obvious to both parties in one way or another - but the name is what ties it together (heh).