There are definitely investors who do this kind of thing to business partners, but they are usually non silicon valley, non tech investors (like a local car dealership owner who is investing in a restaurant). It is really rare among professional investors. It might happen again at the private equity level, where established businesses are being restructured, but there you could argue the value is not with the founders in all cases, or with management. I have little experience at that scale though.

In a startup, the founders, and their relationship with each other and the company, is probably the biggest asset. If an investor doesn't like the team, he just won't invest at all.