Page and Brin collectively own 51.2% of Google's voting power. They seem to be happy with the company direction and its leadership.
While they do not run day to day operations, both are on the board https://news.ycombinator.com/item?id=35810965
With their voting shares, what stakeholders, maybe besides the government, could really exert leverage over them?
(And even if they were running it, it’s no guarantee that it would stick to any respectable values… just “more likely”… but in their case… still very unlikely.)
Instead the stock market and its adherents will be (are now?) our overlord.
Something akin to venture capital, where it makes many, many tries most of which fail and the occasional success moves the field forward.
Presumably investors want more reliable returns from mature companies.
Berkshire Hathaway invests in public companies exactly not like you describe, generally seeking companies whose priorities are evident in dividends not share price.