It does not have a USB port. The serial port is also a non-standard (for serial ports) connector (it is a standard DIN connector). My guess is that the averag

It does not have a USB port. The serial port is also a non-standard (for serial ports) connector (it is a standard DIN connector). My guess is that the average Roomba owner doesn't have a PC with a serial port, and probably wouldn't want to acquire an uncommon connector and wire up a serial converter cable, and then run some program on their PC to dump the firmware image in to the Roomba. The osmo dongle makes the process near foolproof for soccer moms and grandmothers and so on.