I'm familiar with a number of very large deals done basically between C-level to C-level where the scope of IT projects has nothing to do with technologies but entire about cost savings - literally "I will save you $n MM / yr in opex so you can get your bonuses" and other vendors get shut out. Sometimes these deals work out, other times they don't and the executive is basically ousted. Companies with bad politics and enormous cronyism may have worked fine for decades, but they just may not be doing as well anymore unless you're on Wall Street and you make so much money it doesn't matter how it's done.
Software is not the end-goal itself. The point is not to make (or use) amazingly elegant software. The point is to make money.
If a supplier says "I will provide the same service as you are currently getting and cost you $X less" then that's a no-brainer regardless of what service they're providing. It's got nothing to do with technology, and technology doesn't change the nature of that decision.
"Having a throat to choke" is also a matter of insurance. You can't insure against your own incompetence, but you can sue a supplier for not fulfilling the terms of their contract. Executives would much rather negotiate what they think is a tough contract with a supplier than manage a complex project themselves. To that mindset, the removal of risk (because if anything goes wrong they can sue the supplier) is a huge bonus.
It's a totally different mindset from those of us who actually make things.