Good point about root exploit. It's a potential.
Thing is, every Linux server and windows box suffers the same risk... But we don't hear "the sky is falling" about those... Because it's considered a measured risk and security is layered. As it should be.
Hell, people still run windows laptops unencrypted today - which is far worse than an unlocked bootloader on Android.
Don't see why this was removed. Though it does go right back to OP's victim mentality.