They probably got sold on it being "off the shelf" and just a matter of customization and not coding. But the minute they run into edge cases (of which there are likely hundreds given the nature of the product) they just end up stuck.
"COTS software" (commercial off-the-shelf) is the biggest meme in government contracting.
I recall reading a 300+ page PDF RFP for a DMV information management system. The state wanted to convert their legacy VB5(!) system to a modern solution and preferred a COTS solution. I am fairly certain there are no COTS software solutions for a statewide DMV that also meets the legislative requirements of the state.
