"The company is being run solely for the benefit of the shareholders" - bad thing. Boo, hiss. "The company is being run solely for the benefit of the investors" - that's OK, then. Or at least, in some way, it sounds better. Why?
Shareholders own a slice of the company and, usually, get to vote at the AGM. In return they hope for a dividend and/or a share price rise. Investors put their money into the company, in a variety of ways, hoping for a return. Those 'ways' could include shares, bonds, debentures and sundry other financial instruments. In other words, not a lot of difference between the two. And your pension fund will probably be both.
Without shareholders and investors, companies wouldn't get started, wouldn't employ people, wouldn't provide goods and services that their clients want. Without shareholders and investors upstart companies wouldn't be able to challenge incumbents and offer better, cheaper, faster services to the market.
But yet, if you want to run down a company, particularly if it provides service in the public sector, you use 'shareholders' and, apparently never, 'investors'. (For many, this seems to be a coded way of saying that the government could do it better. Apart from the patently obvious fact that usually it can't, where is the money going to come from to finance this state-owned organisation? From an investor more usually called the taxpayer - and he/she won't get a choice about the investment and certainly won't be able to take the money out if it all goes wrong.)
So, next time you hear one of the commentariat or a politico banging on about shareholders, think investors. Use the less emotive word and bring some common sense to the discussion.