Technically, Back to My Mac does work. The problems are most commonly with cheap routers (read crappy) and a lack of knowledge on how to configure and forward ports. That is out of the control of Apple.
Exactly. I've had my router configured to direct all traffic to my home server well before Apple ever introduced Back to My Mac. Set up an SSH tunnel and Network Beacon to have my home iTunes library come up in my iTunes shared libraries at work. However again none of this would be possible without either your only one computer connected directly to your modem to get the public IP or configuring your router properly.