Growth at geriatric tech companies like IBM, HP, Oracle, etc. is largely inorganic, driven by well-negotiated acquisitions of smaller B2B software companies.
It takes MBAs to do this sort of work, and while it isn't for me, I don't think it's the worst business model out there.
You don't need an MBA for the financial/high level business knowledge requirements (though many people involved in this have one), but the people networks that MBA programs provide are very beneficial in getting connected to the right person at the right company.
The main value of an MBA is the network. I think lower tier schools can work well if they are tight knit and the graduates tend to stay local to the school. The top tier schools will just have people making more money at more "prestigious" companies.
It takes MBAs to do this sort of work, and while it isn't for me, I don't think it's the worst business model out there.