Who says they're going to die. Wuhan is a city of 11 million, are they all dead/dying?
Recently, I've been accused of being biased against the current government, but I'm going to contextualise this properly here.
Evacuation can be done, but people need to keep in mind, if it is done, it requires resources, political capital, taking the risk and quarantining. Furthermore, evacuation isn't really out of fear of deaths of citizens, it's to evacuate them from a quarantined city where their citizens are facing difficulty in daily life and are afraid.
In reality, we have some 500 students there. This thing kills only 2%, and that's if the number of recorded cases is not much lower than actual cases, in which case the mortality rate is even lower. Evacuating 500 students can be done. But one wonders the practicality of it or utility, beyond what I've described. I'm not against evacuating them, but people should not panic and they should realise the many reasons why evacuation has happened for some foreign citizens.
Next question that comes to mind, if this nCoV begins spreading as fast in other parts of China. Will the evacuation continue? These governments can't sustain evacuation and quarantine of tens of thousands of their citizens out of China. We have some 30,000 in China. Imagine the scale and cost needed to evacuate them.