The family names could possibly be represented by the descriptions below.
The name Earnshaw could refer to the family's tendency to prefer wealth and status over other things. Catherine marrires the more "established" Linton, and Hindley is only kind to Heathcliff in the end to try to get money from him. They emphasize "earning" over other things. The Lintons however, had wealth, and didn't need such an obvious name to indicate it. It just needed to be a refined, fine-sounding name to represent their wealth and stature.