The 3.0 GPA requirement is a something used by most law schools. It is a bit misleading and you are right to ask this question.
Law school is much different than undergrad in that law school is based on a strict curve. At most schools only 35% of the first year class can have a 3.0 GPA, which means there is a 65% chance any scholarship student will not keep their scholarship for years two and three.
It is also important to understand everyone is smart, hard working, and motivated and on the first day of school everyone thinks they will be in the top 10% of the class and there is no way they will not be in the top 35%, but you do not need to be math major to understand how that plays out when first year grades come out.
With that said you might want to negotiate for more favorable scholarship conditions. As an incoming law student say I will attend if you give me a scholarship subject to merely being in good academic standing or something less difficult than a 3.0.
Many law students do not realize they are paying customers and should do everything they can to get the best deal possible. Congrats on getting a scholarship and your acceptance to law school.