I wonder what is the difficulty in rewriting strncpy uses that makes it take six years? Was it widespread? Or was it more of a long going effort, where it was o

I wonder what is the difficulty in rewriting strncpy uses that makes it take six years? Was it widespread? Or was it more of a long going effort, where it was only changed if there were some changes in the same file? Or is there some other thing that makes it difficult?