Data's technological structure probably wasn't a unique and complex molecular structure like cells & DNA, so why couldn't they have adapted a transporter to be able to replicate Data?
Or even used the same technique they used that created Thomas Riker?
Thats beyond my knowledge of transporters and stuff but The whole Data death has too many questions and what if's. The whole movie wasn't good and his death was just not done any justice.
How about a Why couldn't they transfer his "brain/memory/knowledge" into a hologram, in theory a hologram and data are not too muh unalike in some ways.