The enormity of the response required puts the timetable on a different scale then say, a house fire or building collapse. The sheer geographic territory, varied terrain, limited access and number of people impacted make the response immense and complicated. That necessarily slows the response time somewhat, or risks haphazard efforts that help no one.
Although aid was slow to be brought to some disaster areas, such as after hurricane Katrina, the US government has saved thousands of people shortly after the flooding occurred in Louisiana. If aid was being delivered too slowly, the death toll for this disaster would be much higher than it is.
It is very important that disaster recovery routines are careful not to bring about any harm. The Federal Emergency Management Agency ( FEMA ) on its own has had a fairly bad past performance in acting in response safely and effectively to crises. Therefore, more funds need to be allocated to disaster recovery.
Governmental processes are, by their nature, pretty slow. Even in emergencies, it still takes a certain amount of paper work or protocols to get things done, so it's not instantaneous. Given the size of our federal, state and local governments, there are times when the response is pretty fast,(Sandy) but there are other times when it takes way too long. (Katrina)