You don't need complicated systems to prevent long landings. As Mozella stated, you know exactly what you are doing when you land long, there is no mistaking it. But pilots tend to reason the risk away: it's a long runway, don't wanna go around so close to the ground, any time now..
What we need is a change in attitude regarding long landings, passed down from training management. Send every pilot a warning email when he lands long (it IS recorded in flight data monitoring) and convey the message that landing long is NOT acceptable in any circumstance. That a balked landing is mandated EVERY time you see those last blocks of touch down zone disappearing below you windscreen.
Hammer it into the pilot workforce that just as not being stable at 500 feet and continuing is a 'crime', so are long landings.