If someone (Ubuntu) wants to package and distribute free software (Firefox) in their own format (Snap), the upstream maintainers (Mozilla) shouldn't hinder it no matter how bad the format is - it's not their job.

People are free to distribute Firefox however they want... Without the logo and Firefox branding. If they want to distribute it _as_ Firefox they have to meet Mozilla's conditions

Yes, Mozilla (and any other upstream maintainer who owns a trademark on free software) can set such conditions but no, it's not their job.