The parts of chemistry that work are just rebrandings of physics and the parts of physics that work are just rebrandings of math. Nanotech is a subset of physics with connections to solid state physics, quantum mechanics, materials science, optics etc. I don't get why people say nanotech is charlantry when the semiconductors chip manufacturing industry is top down nanotech manufacturing.

Isn't that basically what "multi-disciplinary" means?

Additionally, scientific niches rebranding themselves is a thing that happens, for examples when Computer Science rebranded itself from Mathematics and Electrical Engineering.

Always has been