Destiny itself had a very long dev cycle. While a lot of it was chopped up into the future expansions there was a lot of quality content that was spread around. D2 on the other hand did not have much of a cycle at all. I dont think they had a choice but to start over with D2 otherwise they would not have all the old content to recycle during expansions. I think its really all by design and to drag out the serious lack of content. The dev roadmap, the coming streamer event, even the 2 to 3 week delay for iron banner 6v6 just drags it all out a little bit longer. Before you know it it will be one year, then 2 years, etc. Imagine if they gave us a 4k and HDR patch for D1. There wouldnt be ANY reason to play D2.