Yeah, but inches are a unit of length and pint is a unit of volume. Therefore a pint is more relevant here. Yeah technically a cubic inch/foot is volume, but it's not the purpose-built one.

To be honest, the volume system in US customary is the only one that makes sense. Everything's power-of-two friendly. If we could revise the others to mesh with that idea then we could have one power-of-10 system (metric) and then a power-of-two system.