Likelihood of confusion is not an immensely high bar for nationally/internationally-known brands (or ones that wish to be nationally-known )in the age of the Internet. Your restaurant gets a string of negative BBB reviews that feature prominently on Google that were actually aimed at someone's product? That's actual harm you can point to. If Alinea were just a local restaurant instead of an internationally-known institution, it'd be one thing, but If I were the YC company I'd take the opportunity to rebrand.