One problem is that segregation only ended for the players;
not the owners- and thats part of whats Boyd is saying; The personality of the leagues was different- and I doubt that all of the things that were done were just for the fans.
The NeL represented a culture- and while it may be great and for the best to integrate, that doesnt mean that something unique wasn't lost.
Also; If the goal was the best playing the best- how would incorporating some NeL teams have changed that?
The NeL teams would have integrated just like the MLB teams, as is evidenced by the story above.
Lastly- if we are relying simply on 'what people want to see' Im sure the Gladitorial arenas would have made a comeback long ago- then you would really see man vs. lion tiger and bear.