@Beta galactosidase I agree with some of your points. But you don't need to change with the times. For instance wanna know how my group plays through the Badab war? With 5th edition the way it was intended right out of the FW books, along with Battlefleet Gothic. Now this isn't for everyone or everyone's play group but nothing is forcing you to use "GW's new hottness" rules set. People including myself have been playing Mordheim for the past 20 years (Man I feel old) and it hasn't stopped us just because GW decided to drop the game.
Playing competitively yes of course you have to use the updated ruleset. But nothing is stopping anyone from doing what they want to do now or in the future. Like modeling with the old marines is a conversion dream despite the age of the models or the scale. They look incredible and very "Grimdark" if that is what you are looking for. When oldmarines eventually do die out, product wise nothing is going to stop me from building armies from the 10,000 year history of the 40,000 millennium and nor should anyone who wants too relive the glorious past prior to the return of a Primarch and the new age of the Primaris Space marine.
(IE I'm very passionate about "oldhammer" models etc I just eat up old citadel and warhammer models from the 80s through early 2000s)
Krash