ITs like most things on the aircraft...wouldnt you like a kind of warning first before an impending failure (if thats the case)?? No point in telling you that you have now hit the limit, nothing you can do now! Its telling you there is an impending situation, yet following whatever procedures you have time to try corrective action to avert this situation.
It is like when you get a Fuel Filter Clog msg....its not telling you the filter is actually clogged, but, if you continue as you are it will clog. (e.g. icing conditions in the fuel may be present, thus possibly causing filter to clog or whatever other reason may be the case)