Why should a for-profit enterprise have any kind of ethical consideration at all? It seems that's your mistake.
1) Shareholders 2) Debt-holders and financiers 3) Executives 4) Suppliers 5) Customers 6) Staff
... and may have a charter or mission, or even an established culture which sets guiding principles.
Various forms of legal power (ownership, right to collectively bargain, fiduciary/oversight responsibility, first rights to assets on liquidation), social power, market power (price negotiation), and individual intention (everyone, even bankers make decisions based on something other than just money) form, a kind of dynamic equilibrium.
So a company is going to end up being or doing whatever the combined weighted intentions of those forces imply.
It's not 'shareholders' that can do anything willy nilly. Sometimes customers have all of the power and indirectly dictate everything. Inversely maybe buyers do: Apple is a dictator to many of its suppliers. Sometimes Unions run the show or have incredible influence (auto industry, government), sometimes the debtors. Sometimes the 'CEO' particularly a founder even without 'majority shares' has considerably more influence than anyone else, with the board afraid to replace them.
A non-profit is almost the same minus shareholders.
I somewhat disagree on a generalized form of "altruism is in the individual's interest" (as in "always"), but for ethical behavior, this essentially means that their is no ethical behavior for companies, only a mirroring of the perceived values of customers.
You need very different actions to not tarnish your reputation when you're dealing with very different customers. Since large companies typically do, there would only be very localized ethics, and they could be diametrically opposed (e.g. "expose & hunt down gays" in Riad, "expose & hunt down bigots" in Berkeley). Ethics is the wrong term here, as the company's actions are not based on principles but on the expectations and principles of the environment, their values are reactive.
The principle "do anything of any moral values that brings me value from others' labour" is still a position wrt ethics, though one can't really call it "ethical" without confusion.
Complete moral plasticity according to what "sells" seems to define our age quite well.
Every member of a physical grouping (e.g. neighborhood, community, city, state, etc.) has an ethical responsibility to other members of that group. Organizations, like individuals, are members of a physical group. Therefore organizations have an ethical responsibility to other members of that group.
Those who are granted special privileges by the group have a higher obligation to the group as a result. Ethical responsibility represents one of those obligations. Corporations are granted special privileges such as limited liability, hence they have a higher obligation.
Similarly, those organizations that are granted disproportionate political and economic power, assume disproportionate obligations. With, again, ethical responsibility being one of those obligations. This is the "to whom much is given, much is required" principle. Also, since an organization with disproportionate political and economic power necessarily has a disproportionate impact on a given society, it is entirely reasonable for those granting that power to expect it to be used benevolently.
The idea of "maximize shareholder value" didn't really kick off until the 80's, and it's been an absolute disaster for the country ever since.
Edit: I looked at the previous replies. All of this talk of 'society' this and 'we' that is of no use whatsoever when you are talking about global phenomena and companies like Facebook/Twitter/etc. Under the given circumstances, the ethical questions are much larger. The problem is probably totally intractable.
Is that what you want, or would you instead prefer that ethical considerations be back on the table?
This "corporations should be cynical sociopaths" idea is even newer than the limited liability corporate form, which is itself a modern invention.
Before the current era of hyper-institutionalization and hyper-legalism there was a concept called "natural law". It basically meant morality, as understood at the time.
When society is prejudiced against a group (not the fake prejudice that society complains about - major broadcasters like Fox and CNN are both probably championing groups who have plenty of support from society, but maybe other groups are actually marginalised but it wouldn't be broadly OK to say it if they were) then it's not society's moral code that helps them (if anything it hurts them), it's businesses that only care about money who will still deal with them.
Most argue that subconscious bias and wealth inequality due to historical reasons are a significant part of discrimination. I've not met someone 'anti-discrimination' who believes there is a deep conspiracy of people working to instill discrimination across society.
In modern times in the western world, conspiratorial sort of discrimination seems to me to occur more in pockets or if the culture of an organisation goes bad and festers. But it's rarely overt or widespread. More subtle and nuanced forms of discrimination are still everpresent of course, but everyone I discuss and work with in these issues knows this all too well.
If that means nothing to you then read the link. Literally killing your own customers to make the line go up isn’t a sound business strategy.