Re: IMHO usually it comes down to...
Been there, did that, left before I got the T-shirt and before I got to be the scapegoat.
At my last job, one of my secondary duties was "IT guy". We were much smaller than the examples from TFA, but still counted on our MRP system pretty heavily. New general manager came in and decided we needed a system change.
I wasn't involved in the selection of the software, which was fine by me, I wasn't a primary user (I was case #3 from the above, I knew it, and I wanted to stay out of the way). It became aparent I would be the lead on implementation. I was fine with the nuts and bolts of setting up VMs, installing SQL server, etc, but then the project stalled. When the status changed from "we're researching customization options" to "AC needs to tell us how to structure inventory part numbers", I realized a double-decker bus called the MRP-express was headed my way, and powers that be were ready to push me to the pavement. Made an unexpected job offer much easier to accept.
Anon, because I'm probably still the scapegoat, just now it's because I abandoned them.