yeah you're going out to a not-cheap dinner and you sit down and the first thing everyone has to do is take out their phone and then stare at it, tapping through some pdf file or a crap website to see what to order. and that's assuming you even brought your phone and that you have cell service, because if not (e.g. maybe you're visiting from another country) then you'll have to ask the server for the wifi password, and then try to type in the password, etc.

you should be able to leave your phone at home or in your pocket/purse when you go out for a nice night to connect with other human beings. restaurants are in the hospitality business. it's basic hospitality.

also: menu design—the material, the font, the way it feels in your hand—is an important part of the overall dining experience. to send paying guests to some mobile website tells me you're trying to make life easier for the business and not the guest.