Why not?
> - Support Bitcoin/Litecoin/Etherum/other popular and trusted coins
The post explains their requirements which these cryptocurrencies don't fit. Do you take issue with their requirements?
> Sync private keys using the same mechanism as messages
AFAIU it's non-custodial and it stays on the mobile client, meaning that there's no synchronization so far (the desktop client does not support these features). This could come eventually, but it's part of their requirements to stay out of the way and let the user handle their coins without trusting Signal.
> this is over the line for their goal of privacy/security
How so?