As mentioned, things get added to the grid all the time, case of the airport was that it was not on a priority list. Yes that is an oversight, but who's fault and accountability we do not know. The onus would of been in the airport to inform the power distribution and if that failed to happen then the airport would be the ones with the hands up, if they was and the distribution failed to add it, then their hand would go up.
But hospitals as I mentioned operate and a designed and planned for such issues with them having backup power supplies. Which is the solution for many installations as many will not have or justify the cost of being upon their own distribution spur.
As for the "we never had to use it before" that's down the testing and covered in previous comments fairly well without repeating it again.
But if you wish to focus upon being able to point a finger at somebody and say it is there fault, then fine. But I and I'm sure many others would not be focusing upon that, though I can appreciate that mentality due to the way media/tabloids cover such and all issues in life. After all, power cuts today are not that common on this scale, decades past and in less developed countries they would be so common that they wouldn't even make the news.
But remember, if the weather forecaster says it will not rain and you go out and a light shower makes you wet - would the forecast be wrong or would we have the mentality to go, that mistake was within acceptable parameters and just one of those things. It gets down to what we are used to and what we accept. So yes, I get that blame need to be lain in many eye's but is that fair all the time?
But then - nothing is perfect - better to focus on getting closer to perfection than expending energy stagnating as too busy pointing the finger.