Besides, the way this tends to happen is when people focus on SEO too much, and on developing value and great user experience too little. Usually, if you do the latter, the former will come naturally. In a way, "good SEO" is increasingly becoming "no SEO, just make good stuff that people love". That's what is becoming equivalent to SEO.
While it may obviously happen that your site gets hit by some Google update even when you don't try to over-optimize for it, chances of that happening are a lot slimmer, and even if it does happen, you still have your good content and quality user experience to stand for (which will help you adapt).
The point is that if you've got customers who know about you as a brand they will know about you even when you disappear from Google. Chances are they will still check you out, and this gives you a good chance to stay afloat even when Google screws you up.
Nevertheless, never say never. I guess it's a matter of picking your battles. If you know you can't win with one particular strategy, pick the game you can win at. Try to be disruptive.
Again, I know it's easier said than done, but at least it might be better than folding.