Kbear is absolutely correct in his historical interpretation, IMHO.
I also surmise that the facts include, probably, key decisions made long ago that were small (at the time), reasonable, yet brimming with unintended consequences, rather than the playing out of some Grande Conspiratorial Scheme.
IBM had accumulated 30-40 years of excellent reputation for superb corporate customer service (whether with typewriters or card sorters!) by that time in the late 70s when, by contracting Billy’s help with their software dilemmas, they coincidentally presented him with the world on a platter. IBM had always fixed promptly whatever the customer needed, building thereby powerful relationships (good business!). When DOS arrived, it was merely another source of other problems, which would need fixing, as it also brought new benefits to corporate performance. Nobody even thought that computers could/would ever be personal . . . or fun. Or able one to do both "old" work easier, or "new" work for new accomplishments. Fun was something you did/had with “toys”. Nobody had ever heard of the Steves and their hardy band . . . yet.
And, do you think there was 1 CEO in a 1000 that “understood” what was happening? I well recall a CEO client of mine who, in 1981 or so, bought a new IBM “personal” computer for each of his VPs, telling each to take it home and "learn" DOS. Oh, sure . . . riiight!
When I asked him what he did with his, he said it was somewhere up on a closet shelf at home!!!!
IT expenses (growing by leaps and bounds) were simply additional costs of doing (new) business
In that same client company, I also recall the distress suffered in IT when the HR department finally acquired Macs for itself, because it wanted to keep much of its confidential documentation under closer control and off the mainframe. Ah, “control”, again.
So the development of the dependence of employees on IT, and IT on IBM/M$ was “normal” until it was too big to be (easily) changed or redirected. Sorta the way things were supposed to be. Most Macs were present then, as I suspect they are today, because some knowledgable individual knew their towering advantages and was able to finagle one or more for specific tasks.
My 2¢