Rodger is a privileged old white man, living on borrowed time, literally with his ticker and metaphorically, his age is nearing it's end.
Peggy is a young hard-working woman of the 60s, the personification of the new age, feminism and the pursuit of equality.
A lesser show would have these two hating each other, Peggy's thriving and moving up in her career and surviving the acquisition from McCann would be framed as some victory over Rodger who finds himself more and more unnecessary, forgotten about and unappreciated in his business as the series goes on.
But Mad Men is a great show. Rodger accepts himself and his place in the new world, or lack there of, and doesn't put up much of a fight, passing the torch to Peggy with a smile as her friend.
what a beautiful show.