You're right in the sense that comparing a logo to a font isn't like-to-like.
However, his point for me is wider than that - if the logo triggers a mental link to something else, even if it's a different concept, that's potentially very bad.
The author is referring in lay terms to the legal concept of trademark distinctiveness (ie, not-being-generic-ness) rather than the concept of conflict between two brands (a different legal principle, albeit one that is clearly important). I don't know whether or not this is deliberate, but either way it's done very well.
Comments
You're right in the sense that comparing a logo to a font isn't like-to-like.
However, his point for me is wider than that - if the logo triggers a mental link to something else, even if it's a different concept, that's potentially very bad.
The author is referring in lay terms to the legal concept of trademark distinctiveness (ie, not-being-generic-ness) rather than the concept of conflict between two brands (a different legal principle, albeit one that is clearly important). I don't know whether or not this is deliberate, but either way it's done very well.