"When all you have is hammer, everything looks like a nail."
A problem afflicting many IT projects which are constrained within a set of standardized tools. Over-simplified statements like "All data storage will go on the SQL database server", "Only vendor-supported, closed source software will be used" and so on.
Vendors are the major perpetuators of this flawed idea, they sell their products under the promise that it can do anthing, will magically adapt to whatever customer sitting in front of them. This narrow-minded line of thinking prevents the discovery of creative, think-outside-of-the-box solutions who unfortunately become burdened by the limitations of the imposed 'tools of choice'.