Wow, that's a pretty sad statement. No wonder our economic system is so fucked up. We've got people out there investing in companies they'd otherwise prefer never existed. Then, of course, there are machines making billions of transactions a day in an effort to game the system. Unless people start investing in companies that they truly believe in, I don't see how this system can do anything but fail in the long run.
This is because there is a lot of money that seeks to invest only in ethical business, so the prices of unethical companies are permanently depressed from their true value, and in the long term the return from their dividends should thus beat the average of the market.
It's scary how it almost made sense.
Luckily, there is a machine out there willing to sell it to you. An evil evil machine.
There are a reasons to sell a shares besides thinking that a company is bad. Sells are also sold to raise capital, this may of course be done by the company itself to raise capital for expansion or in lieu of a loan. This is precisely what an IPO is and companies will also do it post IPO if the cirumstances are right.
But individual or institutional stock holders may also sell it to raise capital even while thinking that the company is doing fine and will likely go up over the long run. If the money was invested specifically for retirement or college for instance, it will be withdrawn (the shares sold) for that reason. An individual or instution may also sell some shares to support diversification or to move to a lower risk investment class while believing the company is most likely to prosper. And of course its perfectly rational to sell your shares if you believe an overall market decline is coming, even if the intention is to rebuy those shares when you believe it is near the bottom
There will be plenty of people to buy stock in any major company without anyone necessarily believing the stock is bad.
Sad, though, yes.