[Suzerain of Sheol]

I wouldn't say "ignore" precisely. You'd use the blunt end to deform the plates so they couldn't move their limbs as well, and if you got an opening, a power swing with the spike had a good chance of piercing through, and the top spike could be used to stab at the mail protecting the joints, which, even if it didn't penetrate, would generally *hurt*.

Oh, and if you walloped someone in the head with the blunt end, they'd probably end up with a concussion. (Which is one of the principles behind fighting someone in plate armor with a longsword -- you flip the sword around and swing it like a warhammer, pommel strikes to the head could at the very least disorient.)