Many one dimensional players are top six, but some can be on the third and fourth line. Look at the Coyotes roster and probably the top three forwards this coming year are really one dimensional.
Many in the top 6 are one-dimensional?
You are arguing for the sake of arguing and not realizing what you are even saying. Pick a random team and their top 6:
Edmonton - I had no idea that McDavid, RNH, Draisaitl, Neal, Gagner, and Granlund are mostly one-dimensional?
Carolina - Teravainen, Svechnikov, Staal, Aho, and Neiderreiter are all one-dimensional?
Philly - JVR, Voracek, Giroux, Hayes, Couturier, Patrick/Konecny are all one-dimensional?
Even for us, Stepan (whether you want him in top 6), Kessel, Keller, Schmaltz, Soderberg, and Dvorak are all one-dimensional? I can see maybe one or two being considered one-dimensional, but by your statement that MANY players in the top 6 are one-dimensional, I don't see that at all.
I see most top 6 players as having well-rounded attributes (will Kessel ever be the best defensive player? No, but he is well-rounded enough that you don't have to shelter him defensively). The one-dimensional players are the ones in the bottom 6 who may carve out nice careers, but not elite careers. The Jordan Nolans, Boyd Gordon's, and others are these types of one-dimensional players that have roles, but are not players who you build around, as they are dependent on others in the top 6 and can be replaced much more easily.