Why do I need to systematically enable 128-bit?

Not using 128-bit would be like driving on an highway way under the speed limit. If your car were limited to 40 MPH and the speed limit were 128 MPH, what would you do? You'd want to drive at 128 MPH obviously! Unlimit your car wouldn't prevent your from driving at 40 MPH if wanted.

It can be applied to SSL. You need to configure your server to enable 128-bit whenever possible. It is a gain of power, it does not suppress already existing possibilities.