Why do people even buy RasPis?
1) Serial port console servers. A Pi2 + StarTech USB 8-port serial is an inexpensive way to talk to console serial ports on routers, switches, firewalls, etc.
2) DHCP/TFTP servers used to remote PXE install the big iron in our data centres.
3) Interconnecting all the NMEA nav/comm gear on the boat.4) Sensor monitoring on the boat (battery levels, bilge, tank levels) and sending alarms.