The money datatypes were created by Sybase in the original SQL server for COBOL programmers. In COBOL, they have a PICTURE clause in their file declarations, which hold display formatting such as commas, currency signs, and decimal points.

Unlike SQL, COBOL is monolithic. The display formatting is done in the same program as the data and computations. But in SQL, we have a tiered architecture for data is passed to a presentation layer that should be doing this.

The money datatype also has arithmetic problems. It does the rounding at the wrong time and computations. This does not happen with DECIMAL(S,P) data.

http://blog.learningtree.com/en/is-money-bad-the-money-datatype-in-sql-server/