At a guess as it was pishing down with rain the runway was contaminated.
If the airport is reporting the runway outside limits yes you can go around in circles for hours waiting for an improvement. With modern runways with grooves the rain just has to let up for 10 mins for the surface to become within limits. You might only have 5 mins to get the beast on the ground before its out of limits again. But was it a grooved maintained runway?
Added to the fact there is issues with runways covered with rubber in wet conditions the Captain made his choice and decided that he wasn't going to be the next one to go sliding off the runway and risk ending up in court with his career finished.
Until you have experenced the joy ride of an aircraft hydroplaning down the runway you will never know the utter sense of lack of control you have. At least on the TP's we can split the throttles and play with the reverse to keep it in a semi straight line, all the time hoping the tyres don't blow out because of the steam eating through them.
I am sure the NPA was well within thier capabilities but quite rightly they didn't fancy their chances on a flooded runway which is covered with rubber.