Scale ?
Not saying that SQL Server can't scale, but it seems to require a deal more effort where the big boys take large scale databases in their stride (which of course can lead to the reverse problem, where using them to manage smaller DB's seems like (and often is) overkill because those systems are built to deal with the really big stuff as the norm, with all the unavoidable scope and complexity in their management tools that this entails).
Biting the hand that feeds IT
