What's the Difference between Philosophy and Science? There is a huge gulf between physics and materialism. Physics describes how matter behaves; materialism is the desire to acquire wealth and comfort — Vera Mont
"Materialism" means two different things. A quick google gives me this:
1.
a tendency to consider material possessions and physical comfort as more important than spiritual values.
"they hated the sinful materialism of the wicked city"
2.
PHILOSOPHY
the theory or belief that nothing exists except matter and its movements and modifications.
the theory or belief that consciousness and will are wholly due to material agency.
You're talking about definition 1, while contextually in this conversation, it's safe to assume everyone else means something more along the lines of definition 2 - which is entirely unrelated to definition 1.
Someone could be a definition 1 materialist and not a definition 2 materialist - and vice versa.