That dosen't mean that they take into consideration 5 years of degradation, additional massive drive setups, or multiple hgh cfm fans...
I have 5 WDB 1 TB drives, 3x 120mm fans, 3x 240mm fans, 1x 120mm 120CFM fan, and a dvd drive, and they are not exactly that low of a power use..
not to mention I may add in some sas 10k drives and a raid 5 card in some day with some ssds....
and I plan to use my psu for 5 years + though at least 2 builds or if not more