Paceline cycling is not inherently safe, and I don't know of any VC advocates who claim otherwise.

However, the danger is borne solely by those choosing to engage in the activity (it's not acceptable to draft behind someone who is not inviting it).

When people race motor vehicles on public roadways, or engage in driving cars too close together, others are endangered.

When people race bicycles (and still obey traffic laws), or engage in drafting, others are not endangered.

That's a crucial difference, I think, and is more than sufficient to alleviate VC advocates who support these activities for cyclists from being hypocrites.