Normal people don't know or care which cloud accounts they're logged into. I don't think I've ever heard of anyone talk about a (personal) Microsoft Account as a positive. People care about syncing their photos between their computer and their phone, sure, but neither Microsoft Cloud nor Canonical's whateveritis does that. People don't know how to get their emails from these extra accounts, iCloud included.

These OS-cloud-account systems may make sense for businesses but they absolutely don't help home users.