Of course it is easy to show how blind management is, However it IT guys are not blame less.
IT has a history of the following bad behavior, that would make management want to find a way to slim its IT Staff.
1. Personal pet projects: This is often a business related project, however there are alternatives that may work better, however it IT worker is too emotionally interested in keeping it going, then giving it up for a better solution. Hanging on to the couple features that has that the others do not.
2. Attempts to make you "Irreplaceable": Sure that program your infrastructure you support is impressive, and perhaps no one else currently will want to touch it with a ten foot pole, and it is your baby, that is keeping the organization running. However in case of accidental death or injury the company is in a bad place, so they will want a better solution. And BTW just because people don't want to touch it, if they have to they can and will be able to maintain it, no matter how hard you make it.
3. Failing to project in the future: If they move to a cloud service, then your job is antiquated. However have you been future proofing yourself. Realizing the role you need to take after that particular feature moves away?
Now I am not trying to blame us IT guys for every stupid business decision... However you need to realize our personal bad behaviors do get noticed up, and influences business decisions.