Shinigami and Hollows are explicitly not intangible - they don't phase through attacks, specifically because of their high Reishi density. It wouldn't make sense to categorize the ability as Intangibility when Intangibility necessitates the character(s) in question to be able to "
pass through things physically." Invulnerability necessitates that the character(s) in question is simply
immune to conventional harm. Bleach characters are technically "immune" to conventional, physical harm as they're spiritual entities. It requires an additional spiritual component to harm them. I don't see how this isn't clicking.
Intangibility = phases through stuff
Invulnerability = immune to conventional damage
Shinigami and Hollows aren't able to phase through stuff = not Intangibility - Shinigami and Hollows are unaffected by conventional damage that isn't supplemented with spirituality = Invulnerable to damage that isn't supplemented with spirituality.
The actual justification itself makes clear that this only extends to attacks that aren't spiritually strengthened. So there is next to no ambiguity on what is being stated by the justification. I'm genuinely confused here.