There are quite a few socially responsible investment (or SRI) mutual funds with good performance. If one wants to be pure on an issue, there is no reason not to use SRI funds.
They are not prudent investments if one's bulk of one's equity portfolio is invested therein. They are inadequately diversified. Many have high fees. But I suppose, if one wants to make a point, one could do that. Anyway, the rap against Bernie is totally unfair on this one.
You're right, but I will relish it anyway. Crazed Bernie supporters make a big deal out of every little thing regarding Clinton, so they shouldn't be surprised if people do the same towards him.