Licensing (alongside the MCA debacle) was definitely a driver, as was the more complex topology for even a simple token ring network compared to a simple ethern

Licensing (alongside the MCA debacle) was definitely a driver, as was the more complex topology for even a simple token ring network compared to a simple ethernet network. Ultimately the brute-force improvement in efficiency given by developing ethernet switching settled the argument, IMO. Once you could practically utilize the bulk of the theoretical bandwidth of ethernet, token ring was toast. Switching was the Pentium Pro of network architectures.