When planning a landing site for each rover mission, NASA considers a variety of factors and makes a best-guess as to the fruitfulness of each site from a scientific perspective.

Clearly a team of brilliant scientists has not failed to consider the possibility of exploring these strange spidery features, but they have decided against it for the time being.

It doesn't really make sense to assess their "strange priorities" as an outsider looking in with very limited knowledge as to how their decision making process actually works.