Nothing systemd has done is preventing anybody from using any asynchronous library they feel like. It's providing local name resolution services. And for very

Nothing systemd has done is preventing anybody from using any asynchronous library they feel like. It's providing local name resolution services. And for very good reasons. By your logic things like NSS is useless as well because programs themselves can read ldap configuration files and /etc/resolv.conf on their own using libraries or whatever else they feel like using.