So lets take, for example, ORCL.
From 2000 till today, ORCL become the clear leader in enterprise: they acquired PeopleSoft, Siebel, BEA, Sun, etc.
On the other hand, MSFT position in enterprise space is in much weaker position comparing to competitors such as ORCL. Enterprises will replace their Windows with tablets, but I don't see them replacing Oracle Database or Oracle Applications (and Siebel and PeopleSoft apps are not so bad).
So Balmer gets B- for his enterprise work. Larry, on the other hand, gets A+.