It's sad that the UK, which invented liberal philosophy, is increasingly accepting of paternalism. It's important that people have an inviolable personal sphere inside which they can live their lives as they see fit. That includes making decisions of which society disaproves.

Moreover, essentially all behavior plausibly has "diffuse negative externalities". We should be very careful about adopting that ("harms others in diffuse ways") as a reasonable standard for banning some behavior.