There are a number of reasons Case was ideally suited for the job:
- Motivation (value)
- Motivation (visceral)
- Artiste (desperation)
- Self-Loathing
Needless to say, they all tie into one another. In my opinion, that's the core of the book, the way that Wintermute was able to see and orchestrate people and situations to bring out what he needed. Neuromancer calls it out when he says
"I need no mask to speak with you. Unlike my brother. I
create my own personality. Personality is my medium."
Wintermute's strength is masks - manipulating others. He manipulated Case, and Molly, and 3Jane, to put the right people in the right place at the right time.
(All quote emphasis below is mine)
Motivation (value)
Any other hacker might be paid off in credits, or drugs, or hardware... things that are fungible. They could always go to the next highest bidder. They could always say "I could do 5 jobs with 1/5 the paycheck for 1/2 the risk of this one... no thanks!" Remember, nobody wants to mess with the Turing heat.
Case, on the other hand, is being paid in something that is unique. No other employer is going to want him badly enough to arrange his surgery. Many other employers might not even know of, or have the contacts, to put Case on the table where his damage can be repaired. Case hasn't been able to find anyone:
The Japanese had already forgotten more neurosurgery than the
Chinese had ever known. The black clinics of Chiba were the
cutting edge, whole bodies of technique supplanted monthly, and still
they couldn't repair the damage he'd suffered in that Memphis hotel.
No one else could, or would, buy Case this way. It later comes out that Wintermute provided the information to the clinic for surgery, and that resulted in the clinic taking out 7 patents - an astounding value. Case knows that. He understands this is a one-in-a-quadrillion chance. He needs it:
"What would you say if I told you we could correct your neural damage, Case?" Armitage suddenly looked to Case as if he were carved
from a block of metal; inert, enormously heavy. A statue. He knew now
that this was a dream, and that soon he'd wake. Armitage
wouldn't speak again. Case's dreams always ended in these freeze
frames, and now this one was over.
"What would you say, Case?"
Case looked out over the Bay and shivered.
"I'd say you were full of shit."
Armitage nodded.
"Then I'd ask what your terms were."
"Not very different than what you're used to, Case."
"Let the man get some sleep, Armitage," Molly said from her futon, the components of the fletcher spread on the silk like some
expensive puzzle. "He's coming apart at the seams."
"Terms," Case said, "and now. Right now."
He was still shivering. He couldn't stop shivering.
Motivation (visceral)
Before Case even experiences the proof that he's been healed, Armitage sets the hook:
"You have time to do what I'm hiring you for, Case, but
that's all. Do the job and I can inject you with an enzyme that will
dissolve the bond without opening the sacs. Then you'll need a blood
change. Otherwise, the sacs melt and you're back where I found you. So
you see, Case, you need us. You need us as badly as you did when we
scraped you up from the gutter."
Offer a man money, then tell him you'll take it away. Not a very visceral deal.
Instead, find a man who has lost nearly everything. Lost his job. Lost his girlfriend. Lost his health and his ability to work. But most of all, lost the thing that makes him him. A painter whose lost his eyes. A singer with throat damage. An artist deprived of the one thing that they were compelled to immerse themselves in.
Offer that man his soul back.
Then tell him it's already being taken away again and the only way to prevent that is to do the job.
He's going to be motivated in a visceral way that few others would be.
Artiste (desperation)
When we meet Case in Chiba City, he's living the desperate life of a hustler, dealing at the edges, always trying to move deals around fast enough to stay ahead of trouble. The bartender Ratz calls him Artiste because of this:
"You look bad, friend artiste," he said, flashing the wet ruin of his
teeth.
"I'm doing just fine," said Case, and grinned like a skull.
"Super fine." He sagged into the chair opposite Ratz, hands still
in his pockets.
"And you wander back and forth in this portable bombshelter built
of booze and ups, sure. Proof against the grosser emotions, yes?"
Molly understands that being in Chiba had stripped Case down to his basics, the desperate animal that Wintermute needed:
"Guess you're kinda like he was," she said. "Think you're born to
run. Figure what you were into back in Chiba, that was a
stripped down version of what you'd be doing anywhere. Bad luck,
it'll do that sometimes, get you down to basics."
Wintermute hired Case because he's a cornered animal. He will fight with everything he has because he had nothing left to lose.
Self-Loathing
In the end, it is the mixture of this motivated desperation and Case's base skill set that pushes him to transcend his limitations and become what Wintermute needed:
He came in steep, fueled by self-loathing. When the Kuang
program met the first of the defenders, scattering the leaves of
light, he felt the shark thing lose a degree of substantiality,
the fabric of information loosening.
And then – old alchemy of the brain and its vast pharmacy – his hate
flowed into his hands.
In the instant before he drove Kuang's sting through the base of the
first tower, he attained a level of proficiency exceeding
anything he'd known or imagined. Beyond ego, beyond
personality, beyond awareness, he moved, Kuang moving with him,
evading his attackers with an ancient dance, Hideo's dance, grace of
the mind-body interface granted him, in that second, by the clarity
and singleness of his wish to die.