It will take time for people to realize because Ethereum is so much more complex that Bitcoin. But it will happen eventually and inevitably imo.

For some applications, yes. I believe Stellar (XLM) is the future for transferring money across borders.

Why would any bigger institution (like a bank) ever use a non-private chain where everyone can see how much they have and how much they sent to do transactions?

Blockchain is being taken up by banks, with projects such as r3-corda, but is is a private chain, with no shitty "coin" for morons to speculate on and thus gets no attention.

Ethereum will allow for private transaction so institutions can conduct business on it in an opaque manner.

I'll believe it when I see it. Right now it seems like nobody cares about privacy in the ethereum space.

What are you talking about? There's tons of advocation for privacy.

the repo looks pretty dead https://github.com/ethereum/go-ethereum/graphs/contributors

That's pretty selective lol. Why not use one of their main repos? It's almost like you have an ulterior motive.

the official ethereum client is not one of their main repo?

what is?