The rift between the logical structure and the physical structure is something of a necessity. There are so many ways to physically connect devices that if the logical structure reflected the physical structure, it would be rare for unlike hardware to be able to communicate. Prior to the widespread adoption of TCP/IP, the logical structure did often reflect the physical media. The problem came when connecting equipment made by two different vendors, which was often difficult and unreliable. The TCP/IP suite of protocols was a true step forward in interconnectivity, and in those days, about as much as people who struggled to get things to work could have hoped for. Also, in the early days, new protocols using TCP/IP for transport were sprouting up left and right, up until the late nineties, when innovation kind of slowed down, and it seemed the Internet started becoming more about the content available than the fact that it was then easy for everyone to talk to everyone. The separation of the physical from the logical also made it easier for the two to develop independent of each other. Its also worth noting that without a separation of logical from physical, the Internet would probably not have scaled at all to its current scope. Such separation was necessary to transcend the physical limitations of communication media. Its true that the people engineering the logical structure of the Internet are fairly agnostic about the physical medium used to communicate. Bits per second are more a concern than the medium used to get those bits to their destination. Really data communications and telecommunications are two separate albeit related fields. However, the TCP/IP suite of protocols was initially put together with the thought in mind of being as open ended as possible, allowing for extension and expansion. In my own view, this may have been a response to the restrictive engineering efforts of earlier times, and the limited ways in which those efforts were ultimately usable. The mindset seemed to be that if you allowed for growth, what you accomplished was more useful for everyone.