Because you thunk governements having power over currency is a good thing? At least with corporations you can choose to deal or not with them, that's the dream.
That position beaks down when the corporations control the means of transaction.
It would be a different story if Libra was a bunch of companies making an arrangement to accept each other's individually-issued cryptocurrencies, but instead its a cabal issuing one scrip that they all control.
I don’t have too strong an opinion, but certainly it’s a well-understood thing.
What specifically is bad about it? The ability for governments to seize money or interfere-with/surveil transactions looks like it will be preserved via Libra’s KYC/AML surveillance/protections.
I suppose for people with very large amounts of money, they might disagree with their government’s currency policy re: inflation/deflation. But for those people, a huge range of investment products exist to hedge.
For example, Experian has your data and is a significant factor in whether you can get a loan. You never chose to do business with them.
How/why is a corporation better? A corporation's main goal is to profit.