DB: Great question, and IMO the answer is "it depends on how you do it."
I understand what you're getting at, but I believe we need more clarity, or we will lose this debate with the Left.
Judicial activism occurs when legislation is conducted from the bench, in violation of the Separation of Powers.
Throwing out such activist, judicial legislation, is never "activist" itself, regardless of the magnitude of the consequences.
If the Right doesn't get clear on that and consistently make that case, the debate will be framed by the Left as one set of activists against another. The Separation of Powers is the device that balances our democratic republic. Violating the Separation erodes both our our democratic (small "d") and republican (small "r") traditions, to the detriment of all.
We'll have to agree to disagree on this point. I think there are ways to undo judicial activism without in turn setting a precedent ... of grossly ignoring precedent, in the manners I have stated previously.