Because it’s even more hypocritical about it.
My $0.02:
(Right) Libertarians are “leave me and mine alone, also provide more police to protect what’s mine.”
They tend to not really have any real economic policies. I mean, they’ll talk about the sanctity of contracts, but that’s not an economic policy any more than a stack of used 20s is an economy.
Neoliberals take that general idea, scale it up to the nation-state, and provide economic chops via Mises, Hayek, Milton Friedman, the Austrians, and the Chicago School of Economics.
They upended libertarianism by redefining a corporation as an economic person and declaring its rights to be a participant in the economy (locally, regionally, and globally) in its own inalienable and total right. Because when you get down to it in their equations, that’s all a “person” is. A unit which buys and sells things and shows some sort of preference. Scale is irrelevant. (Just one of the ways that neoliberal economic theories crumple into dust and blow away when exposed to reality.)
Neoliberals want to shut down government and governmental restrictions on “economic actors”, except 1) to expand the neoliberal system, and 2) to protect those actors who can afford to pay for it. (In more advanced neoliberal systems, even that is degraded, until police forces and armies are totally privatised, which anyone with an awareness of history will recognise as a return to pre-modern systems, going back to outright feudalism.)
Which is to say, that built into neoliberalism is a deep and abiding love of police to protect capital, and armies, to acquire more capital. The difference is in who they answer to.
While (right) Libertarianism obviously naturally devolves into a war of all against all almost immediately, neoliberalism assumes it, and designs its political and social structures accordingly.
Naturally, corporations and billionaires have always loved both neoliberalism and libertarians, but for different reasons: Libertarians are easily manipulable idiots, by and large. Neoliberalism is the structure which is by its nature both authoritarian and libertarian, depending on how much freedom you can afford to buy. As billionaires can afford all of the freedom, they don’t see a problem with it.