Bands age. Like all of us. They go through phases. Like all of us.
If one phase ends and another one starts then I'm against dwelling on the past forever - that's a bit like wishing that Brad and Jennifer, errrm, Angelina were still an item. Angus&Axl/DC want to record a new album, that is legitimate. If all they did was a Greatest Hits tour with Axl singing Bon Scott songs it be a different matter to me. Axl does a good job singing/screeching that stuff, you know how limited yet tasking the role of a vocalist in AC/DC is.
I don't have issues with Steve Morse in Purple, he has been longer in that band than Blackmore (even taking all his various stints together) and the music has adapted to his style. He's no dark maverick like Blackmore and no drugged charming angel wildly veering between breathtaking inspiration and utter failure like Bolin, just a gifted musician working hard at his craft. Nostalgia aside, I don't think that Blackmore would have much to say with DP anymore, his days of inspiration are behind him. Never mind, anybody who wrote something as idiosyncratic as the Burn riff is entitled to some inspirational rest.