I would guess that someone who contends that they have never experienced accurate loads with Partitions has:
little experience or,
has issues with their loading techniques or,
simply has never really used them.
In ~50 years of reloading, my experience has shown Partitions and Sierras to be easy to find accurate combinations in a wide variety of calibers and rifles.
Well, I'm here to tell you that absolutes (except death and taxes) are wrong. I've had several instances where NPs just don;t shoot accurately in several calibers and rifles. As to Sierras, never used them...