There is just one exemption to this rule – if you’re going to a bar where Mojito is the house specialty (like in Mexico or something), then, order one. Otherwise, never ask for a Mojito anywhere else. It’s not that Mojito is a bad drink. If prepared properly and with complete, non-substituted ingredients, it is one of the best drinks to order, actually. But like Liza said, it is a house specialty drink which requires a bit of time to make and a lot of fresh ingredients. The motive as to why you’re being told not to order it is the “freshness of ingredients” reason.