Your distribution has configured your GDM or Getty to have some dependency on something that ultimately waits on dhcpcd/network-online.target.

It’s not really the fault of systemd; it just enables new possibilities that were previously difficult/impossible and now the usage of said possibilities is surfacing problems.

It is the fault of systemd that there's no interactive control.

On other inits, I can hit ctrl-C to break out of a poorly configured setup. Yes, it's more difficult when there's potentially parallelism. But systemd is not uniformly better than everything else when it lacks interactivity.

And it might not be better than everything else if common distributions set it up wrong because it's difficult to set it up right. If we're willing to discount problems related to one init system because the distribution is holding it wrong, then why don't we blame problems with other init systems on distributions or applications, too? There's no need to restart crashing applications if applications don't crash, etc.