Bankers back each other and know how to fight for themselves and the group. Programmers generally don't. You'll see a engineer rat another engineer out to management when there's nearly nothing to gain. This has been shown in companies with peer performance reviews: the bankers and traders give each other top ratings, while the programmers tend to beat each other up. It's not that bankers are better people and won't stab each other in the back; it's that they understand that information is power and won't do so for free, or for meaningless stakes like transient managerial favoritism.
A typical, politically-inept programmer will say, "the low performers are Alice, Bob, and Charlie", just because he's asked. You don't have to offer him anything. He ends up losing in the deal for two reasons. First, if people find out that he's a snitch who tried to endear himself to management by selling others out, then everyone will hate him. That's just human nature. Second, low performers can be good for your job security because (a) you don't have to outrun the bear if layoffs or stack-ranking come-- you just have to outrun the other guy; and (b) they can anchor compensation favorably. The fact that a mediocre investment banker gets $500,000 per year means that a good one makes millions. That's how you play a large, rich organization that isn't going to die because of a few passive low-performers. You want to move against the active low performers (i.e. those who create problems for other people) and the politically dangerous, but it's generally good to protect people who are benignly below-average because their making average wages puts a case forward for you (as an average or better performer) to make above-average wages.
A banker won't give that kind of information (who's performing, who's a little weak) up unless there's something to be won from it. If you're acting politically optimally (and not afraid of being a bit of a sociopath) you know that there are times when it's best to protect low performers and times to sell them out. In peace time, it's usually the former.
As for academics, they make the software engineers look politically savvy. They've performed so poorly, as a tribe, at convincing the rest of society that they have any worth, that their whole industry has fallen to shit. If I were to choose a specific mistake, I think the biggest fuckup on the academics' part is making it so goddamn obvious that they consider research to be their "real work" and teaching to be that onerous grunt work that they got stuck with. That works for the research rainmakers who bring in millions in grants, but devaluing teachers has led to the adjunct market.
The older generations of professors expressed distaste for the teaching job, as if it were commodity grunt work, and the universities have responded in kind by treating the teaching as commodity grunt work, i.e. the "You said it" retort-- and, at the same time, realizing that they could then do without all these medieval history researchers who were mediocre teachers.
If academics had any political or social skill whatsoever, they would have never developed that culture that devalues teaching and especially undergraduate teaching, because even if they considered the research to be their real work, the rest of society considered the teaching to be their real work, and by devaluing it they basically challenged the rest of society to unemploy them en masse. See, undergraduate teaching is valuable in its own right (intangibly) but it's also a marketing effort; if you convince the next generation of leaders that literature is important, then maybe they won't unemploy people who study it full-time. But if you decide that teaching the hoi polloi undergraduates is beneath you, then you risk getting fucked (deservingly) 20 years later when those undergraduates become state senators or college donors and decide that what you've been studying is unimportant.
That said, the calamity of the tenure system is that the older generation (who created this obnoxious culture) was unscathed and it was the younger generation who saw their job prospects turn to vapor. I hate academic tenure for that reason: it seems almost designed to make the rising generation pay for the entrenched generation's sins.