The main point however is that there must be a clear limit, whatever that number is.
There lies the problem. It's difficult to prescribe a "one size fits all" solution, as is often the case in aviation, bearing in mind that different modern aircraft have very different capabilities. The capabilities of recent civilian aircraft far surpasses what the military have at their disposal.
As I wrote before, if a 1,000' limit is mandated across the board, there would be little point in any further research and development for the purpose of making aircraft safer and more capable with respect to poor weather operations.
Again, I'd maintain that this wasn't actually the root cause of this incident.