Fair enough, Steven...
I believe, Miles just got tired of playing bebop. He was a visionary...do his own thing, just like Tristano did. Like in all music, there are leaders and followers...that's how music grows. There is nothing wrong being either one.
Adding a thought to the discussion...
One thing is a fact and we must understand that during the glory days of Jazz development musician had to make a living, which, looking back, unfortunately adds to their body of work. Some might be looked upon by critics or purists as substandard and did not reflect their respected talents. Some great Jazz musicians, instead of 'selling out'( I wish I could put more mildly
) and/or deal with the racism at the time, ended up in Europe to make a living and do their thing. BTW, some Blues musicians still do it to this day.