The "one-button-saves-all" approach is magical thinking and not appropriate to aviation
I would still tend to think that a "panic" button could be useful in some cases where the pilot simply doesn't understand what's happening with the plane. The Airbus chief test pilot and 6 fellow airmen were killed in such an occurrence (ok, it's a bit of oversimplification)...
Still, there are some cases where a clean way to reset the systems to basic operation (throttle are in sync with engine thrust for instance...) complemented some
optional aditional and basic help to recover from emergency situations (stop the plane NOW, get to level flight NOW, Go Around NOW) could save the day...
Just my 2c