Some companies uses bare hostnames for internal systems. Those same companies use HTTP Basic auth to log into those systems. And some routers have weird behaviour for DNS resolution, like prioritising .net as the default TLD.

I ran into a situation where, even on VPN, going to https://<company>vacation/ on my home network would take me to https://<company>vacation.net (a valid domain). It would have been trivial for the owner of that domain to phish for credentials.