It's about whether a person should be applauded for doing earning-to-give or whether earning-to-give should simply be seen as a way to "enhance his reputation and status". Those cultural norms matter. Having the wrong cultural norms make people die who would otherwise be saved.

I'd say it's more about a public figure who transfers billions worth of stocks to a for-profit company that they own while making a big show of it should be applauded or we should be wary of their intentions.

It's also about why EAs all fell head over heels the moment they heard the word "give" in connection with some transhumanist dog whistles such as "advancing human potential" and "live much longer and healthier lives", contravening to their own stated core principle that charitable donations should be done in a way that produces measurable benefits to people, not warm fuzzies.

And yes, finally it's also about this so-called liberal communism thing, which I prefer to call modern aristocracy:
should we, as a society, encourage or discourage a system where basic services depend on the grace and benevolence of few elites who can grant or withdraw them of their own accord, without democratic oversight? Should we encourage or discourage overt political lobbying by private organizations with billion dollars worth of endowment controlled by elite interests? Whether you agree with Zuckerberg's object-level political positions, such as the Startup Visa Act, isn't political advocacy by very large scale lobbying something to be worried about?

There are also issues of perverse incentives. If, say, the school system becomes dependent on a steady stream of donations that come from the dividends paid by Facebook stocks, then school employers and users alike will have a massive vested interest in Facebook's continued profitability, creating a whole new level of "too big to fail".
The day that Google finally manages to make a buzz/g+/whatever that works, or that some guy in their basement comes up with a disruptive idea that makes Facebook-style social networks obsolete the way that cars made horses obsolete, who will the government, teachers trade unions, parents organizations, etc. side with?
Sure, Google can play Facebook's corporate charity trick too, and so can Microsoft, Apple, Amazon, etc. The guy in the basement with a bright idea can't. Should we resign to a future of corporate neo-feudalism?