A company works for its shareholders, which are a very restricted group, and public funds work for society. Intuitively, the outcome is clear. It's also supported by actual data: wages stopped rising in the US in the 1970s, while productivity kept going up; this is correlated with the introduction of concepts like "shareholder value".
To add to the above: Pretty much all companies benefit society; it's hard to think of counter-examples.
Sure, oil companies spill oil sometimes; but they (should) have to pay for that.
Big telcos tend to have monopoly status, and exploit consumers, but they do that not because they are companies, but because they are in a patron-client relationship with the government.
Some companies produce tremendous benefit to society; others produce small benefits, which matter a lot in the aggregate.
