Duran Duran was much more talented than many people realized back in the day. Their pop, boy band sort of image kept a lot of people from listening to them.
They've only gotten better over time.
So far as John is concerned, it isn't just his skill at playing the instrument, but it's his ear. It's his response to what is generated by the other musicians and the lines he lays down for each song.
For instance, Rio. Listen to song without the bass. It's mostly a relaxed but upbeat sound until you get to the saxophone solo, and some of the meter of the vocals.
The bass line that he wrote for the song really helped shape it into the high energy song that it became. If you listen to only the bass line, nothing else, you would never imagine that it would fit a song anything like Rio. That is if you can imagine it that way. With already knowing the song, it's difficult.
My point is, if you listen to DD, from the beginning to now, you'll see that JT puts down the perfect line for each song, every time. He is whatever the song needs. A lot of musicians simply toss their main style into every song.
My current fave right now, with a great bass line. Another Great JT line. Also, some of the Blue Silver / Chauffeur synths. Great song, with every single thing even vocals dead on perfect. Great build up as well, emotional.
Before the Rain.
http://youtu.be/qXxlfdvnwNw