I think some people want to see this film so badly they are willing to throw away all reason.
The age difference between Norma and Joe is key. There's a kind of revulsion Holden feels, and a hunger Swanson communicates that makes the relationship pathetic and fascinating. A Jake Gyllenhall/Michelle Pfeiffer teaming could communicate that. Having a 75 year old Close paw some young stud is grotesque, dinner theatre Sweet Bird of Youth.
Others argue who cares about Cecil B. DeMille. He's essential to the film's depiction of the Golden Age of Hollywood and how it moved on from the silents. Lose that and you're losing part of what made the film great.
Why reamke "Sunset Boulevard" if you're going to throw away the things that made it work.....just to have an overage, inappropriate leading lady jut cuz you love her.