A paragraph says the following: " Most development projects do not address the issue of decommissioning at all. As a result, systems live for much longer than anyone would have imagined. This is how so many systems were in danger of crashing on the first day of the year 2000 none of the developers had imagined that their systems would last so long. A perhaps more extreme example is that of the United States Department of Defense, which is reputed to have had more than 2,200 overlapping financial systems at one time. Efforts to reduce this number have not been very successful, proving that it is much harder to kill a system than to create one. " Why do you think the that it is "much harder to kill a system than to create one?"