Here's why:

* Magnetic stripes are formed at mid-ocean ridges where new oceanic crust is created.

* Subduction zones are where oceanic crust (older and denser) dives back into the mantle.

While magnetic stripes are a key piece of evidence for plate tectonics and the process of seafloor spreading, they are not the locations of subduction zones. Subduction zones are marked by deep trenches, volcanic arcs, and earthquake zones.