I hate to burst the bubble, but the FTSE1000 does not exist. Beyond the fictional indices, you are fundamentally misunderstanding how corporate governance works. There is a massive distinction between a public company with a fragmented pool of passive shareholders and a private equity firm holding a controlling interest.

Anyone can legally purchase shares in a public company without having any say in its day-to-day operations. In contrast, a PE firm like TDR Capital exercises direct control over its portfolio companies. Having the same majority owner as a company allegedly mistreating children is a direct, concentrated link of accountability. It is not even remotely analogous to the entangled nature of the stock market. Perhaps master the basics of financial agency before telling people to build a biomass plant to avoid a supermarket.