Guacamole is not intended to replace normal remote connections... It provides additional features that target people whom can't reasonably use RDP or VNC themselves ...

it provides access management so you don't need to expose the server, or the user/passwords, to gain access... You can also record the sessions ... And some other neat features... None of which really soon to replace a direct connection made by a technically savy individual between to machines on a network he controls.

But imagine the benefit for schools -- high schoolers can be given access to a virtual machine, without installing RDP or similar protocols on the students machine, and without giving them virtualization tools that might allow when to bypass student safety protections