[rfurtkamp]

Now i am Old School but can someone explain to me or justify the current fad of putting " light " rails on SD pistols

Those are accessory rails, not just "light" rails. Lasers, lights, and I'm sure a host of other options will be envisioned to put on them.

It's a matter of having that option. You don't have to use them, but if you want them, the gun has to have 'em.