Microsofts offering is also a a bunch of bundled components, it's not as open because in order to achieve a "fully integrated suite" or at least as close as they could come as a viable commercial proposition, they had to restrict how open it could be.

There's the short term advantage of going monolithic.

There's the long term cost of being monolithic.

There's the long term benefit of vendor lock in.

There's the long term benefit of choosing of choosing closed interoperability mechanisms to stifle competition,

Go have an off the record honest conversation with some of the boys from the big closed software vendors. Are they happy with how dead open computing is, I'm guessing not...