If you are content with letting any company or executive off the hook with everything because “the purpose of a corporation is to increase shareholder value” then you have given up on democratic society.
I would only put trust in organizations who are not for-profit companies if it's for important things. I couldn't care less about food-delivery services for middle-class and above, but for hospitals, prisons, water, electricity and so on, you can't have (well, you can [look at the US], but usually doesn't turn out great for the people, only the stakeholders) for-profit companies running them as the incentives are all misaligned.
Early in the US history, all companies existed through acts of congress and thus were implicitly for the betterment of the USA.
The theory of corporate ownership... Or at least the fashion trend... Has changed through the years. But many still hold onto the old ideals.
We live in a democracy, which means that we can change the 'purpose' of companies as long as enough Americans agree on it.
As such, your argument cannot assume a particular definition or purpose of companies. Instead, the question should be... Is the current for profit model really best for America?
Regulation usually is used for help controlling that (and regulation is normally set by representatives of the people in that state)
You're outlining a healthy perspective on change, which I thank you for. Also means we can continue to push for more better changes.
The reason companies do this is not to be a friendly company in general and care about the world and it's people. If that was the point, they would have created a non-profit or similar. The criticism of hypocrisy should come when they make those ads instead.
Look at the Activision/Blizzard situation where a player was banned for speaking for a cause they believe in, they release different statements in different countries (one pro-China in China and one not pro-China in the US), and applies different rules in different cases where it makes sense for the market. In China, shouldn't speak about freedom for Hong-Kong and in the US, it's important you support LGBT. The company will reflect that in their advertisement, where they want people to buy their products.
Apple wouldn't be doing it if it cost them significantly, as we see with them compromising their supposed values under Chinese pressure.