Noted in a comment at SlashDot:
One day, I set up a PPP over SSH tunnel between my home computer, and my desktop at work. Transferring large binary files from my office network to my home computer was much closer to the original 3Mb/s speeds.
There is no legitimate reason for the above. I t would be a great opportunity for a malicious insider (e.g. to transfer proprietary data, to bypass access controls) or just a dumb-ass insider (e.g. to get around content filters).
Some sub-set of internal users may need SSH access to the organization’s servers that might be past the firewall. The right thing to do is have to have firewall rules to support that explicit user group and their destinations.