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?
Replicators work on the mollecular level. Presumably Data, like people, has quantum level components that cannot be replicated and would be "lost" in the translation. It also seems building a stable "posotronic" brain is harder than it seems as Data did it when he built Lal and she ended up failing.