Easy. It wasn't "scrapped". Changes were made meant to accommodate all further modes they added that negatively impacted Secure, such as the following:
*Adding battle high
*Awarding points for kills instead of holding capture zones and breaking nodes
*Increasing mount speed
*Adding the middle ramp to each base
*Adding forced freelance to everyone
*Reducing premade maximums
Because SE wanted to innovate, try new things, and make changes under the notion of "increasing accessibility" and all they've done is lure more people who don't wanna be there in the first place.
Let's not sit here and dote on SE like their decision-making is always for the better.