Large cargo vessels do try to avoid bad weather, even though they can sail through most of it. It's a crew happiness, risk, and loss avoidance concern (knowing these companies, probably mostly the latter two!).

I was on a cargo ship in the pacific which diverted into the Bering Sea to avoid some weather instead of skirting just south of the Aleutian Islands as planned. The captain gots orders via satellite from a land crew that's crunching the numbers of risk vs extra fuel costs at all times for the fleet. The first mate was frustrated by how this all works. He said (English not being his first language): "This is terrible! We never get to decide anything for ourselves. We are like Muppets!". I think he meant "puppets"...