MAD has worked partly from the great reluctance to press a button and kill millions of people. But also because millions of your own people will be killed in response. The increasing use of space for peaceful purposes will help bolster a MAD deterrent. Space is very similar to cyber and getting closer to cyber all the time. We don't pretend that cyber can ever be demilitarized. OTOH we do not have MAD for cyber, and it is probably not possible, cyber is too robust. We need to make space similarly robust.
I agree with the sentiment on robustness. Unfortunately, as Spock once said, it is always easier to destroy than to create. Space is VERY expensive. Most satellite cost millions if not a billion dollars to build and launch. It takes very little to disable them from the ground if you have an adversary with the inclination to do so.
Space will never (or at least in my lifetime and probably the life time of my children) be populated to the point where the reluctance to press a button that exists for nuclear deterrence is present. So we can spend Trillions (that’s what it would cost) to have all our space assets armor plated, or we can stay in our budget and work all the cost, schedule, and performance trades to get best bang for the buck, and try to use other forms of influence (economic and political power) to shape the environment so that we don’t have to spend the treasury on space battleships that are obsolete shortly after they are launched.
Congress wont approve the trillions (and arguably shouldn’t), so the reality is we figure out the best way we can afford to deal with it.