Because high future valuations allow companies to raise capital and do useful work in society.
[citation needed]
AMC
Beneficial to whom?
In general, to its users, hopefully without also being detrimental to society as a whole. But my point here is mainly "shouldn't the goal of a company be to produce a useful product or service rather than simply to make money for its shareholders?"
That’s the purpose of a commercial company. To return money to shareholders.