The main reason I hate the Supreme Court's overreliance on the use of dictionaries? Dictionaries aren't meant to be prescriptive, they're meant to be descriptive.
Suppose a contract requires that a party google something as a part of its services to the other party. Did they mean that the party would search on the internet generally, or did they mean that the party would specifically use Google for all of its searching? Well, if you look in the dictionary, the first definition that comes up is the brand-specific one. However, Google has also made a concerted effort over the past few years to avoid genericide, the appropriation of trademarked terms for general, non-specific usage (also, not in the dictionary).
It's a lazy, faux-originalist way of figuring out the meaning of words without actually having to delve into what people actually think and how words are actually used.