This seems to be build on the (IMHO wrong) premise that non-investing it will somehow change the minds of these non-sustainable businesses, where in reality, by investing into a business, you get voting rights to actually influence in which direction a business is heading.
Thinking about it the other way: By not investing is such non-sustainable companies, only the people who don't care will do. And they will actually get the companies are a discount.
> by investing into a business, you get voting rights to actually influence in which direction a business is heading.
Or you just get entangled in the political battles already happening in that company, which will take more effort and time to untangle to enable you to actually steer the ship into some kind of sustainable business.
So not only you'll be fighting the lack of a sustainability mindset/processes but all the entrenched political powers that made this mindset be realised. Throwing good money at bad stuff is not really a good prospect for investing, better to invest in places that aren't dirty from the get-go.
But the companies who actually do good stuff need money and I'd rather give it to them than the others.
I also think that investing in these companies will rather change you than you will change them.
Thinking about it the other way: By not investing is such non-sustainable companies, only the people who don't care will do. And they will actually get the companies are a discount.