The Imprimerie Nationale has, in France, a status much like that of an "official ruler" about typography. Some of its recommendation, based on centuries of French typography, are then almost mandatory (or are perceived as such).
This is the main reason why those recommendations are implemented in the French module for babel. Other modules don't provide this type of enhancements because there's no "necessity" for them. For example, the German module provides shortcuts for typing umlauts, German quotes and break points in words, but no "typographic" command.
The Spanish module has many features similar to the French one, just because Spain has a "language ruler", the Real Académia Española. (There are proposals of a Mexican module just because they don't like the way the Spanish module does, for instance.)
Why isn't there a
\th command in the English module? Because good typography doesn't use an upraised "th", which is a relic of the Victorian era which came again into light because of word processors (see this TUGboat article by Peter Flynn). What about
\degree for the temperature? Because such a command can't exist, as English speaking countries use different units of measure (metric or imperial; in some countries it's metric and imperial).