I still hear people trot out the old line that the sole responsibility of a business is to act in the best interests of its shareholders – by which they usually mean maximising short term profits at the expense of all else. Here in the UK, at least, this isn’t exactly true. In the 2006 Companies Act, directors’ duties are defined as:

S172 Duty to promote the success of the company
(1) A director of a company must act in the way he considers, in good faith, would be most likely to promote the success of the company for the benefit of its members [ie shareholders] as a whole, and in doing so have regard (amongst other matters) to—
(a) the likely consequences of any decision in the long term,
(b) the interests of the company’s employees,
(c) the need to foster the company’s business relationships with suppliers, customers and others,
(d) the impact of the company’s operations on the community and the environment,
(e) the desirability of the company maintaining a reputation for high standards of business conduct, and
(f) the need to act fairly as between members of the company.
[Emphases are mine]

In other words company directors are obliged by law to consider long term issues, employees’ welfare, communities, the environment and the company’s own reputation when making decisions.
So CSR isn’t just a like to have, it’s the law.