Reason builder underclocked RAM in pre-built system?

[gx240]

I'm examining a pre-built system with two 4gb 1600mhz sticks of ram, but for some reason they're set at 1333mhz in the BIOS (UEFI). I checked the motherboard specifications, and it supports 1600mhz. Is there a good reason why the system's builder would underclock RAM like that? Is there any reason I shouldn't set it to 1600mhz?

 

[C12Friedman]

1333MHz is the default for higher frequency ram. Most often it will run at that speed until XMP is enabled - I'm simply going to guess XMP was never enabled here.