Whether or not you want to be discoverable with your real name is a participatory concern, not a problem with a platform.
Diaspora isn't feature-complete to even compare on paper to facebook; it works more like mastodon, or twitter.
Being discoverable should be something you can opt others into, not assume at a base level. A medium of contact should exist, that individuals control as a locus of contact disbursement.
you want my email? Ping a request to my public card