Shipping costs ?
Okay maybe
Deployment in high density DC ?
For the most part, the power density is too high for data centers unless it is an exotic density DC (expensive). 42 kw per rack is off the charts.
That said you may have a speciality application in mind, for example sharing a data center with some existing or planned low power density application.
Give us a bit credit we know what we're doing.
Yeah, you probably do. I mostly meant it as a reply to the guy trying to figure out how to make them quieter in a home environment. Mod the case and use bigger fans.