My comment:
Semantics! (No pun intended.)
e-prime improves one's writing, improving one's writing has nothing to do with semantics, therefore one shouldn't promote e-prime as a general semantics practice.
The author confuses cause with effect. He takes one single effect of a practice, claims that this effect has nothing to do with the science that the practice forms part of, and purports that for this reason the practice should no longer form part of that science.
To reuse my analogy from Argument #10: Eating healty food makes you feel good, but feelings fall outside the science of nutrition, therefore one shouldn't promote healthy food as a nutritional practice.
Definition of Semantics (from Wikipedia):
In linguistics, semantics is the subfield that is devoted to the study of meaning, as borne on the syntactic levels of words, phrases, sentences, and sometimes larger units of discourse, generically referred to as texts. As with any empirical science, semantics involves the interplay of concrete data with theoretical concepts, and specializations have developed that focus on different parts of that interaction, for example, the semantics of natural languages and formal languages, respectively.
Depending on the perspective taken up, semantics may include the study of connotative sense and denotative reference, truth conditions, argument structure, thematic roles, discourse analysis, and the linkage of all of these to syntax.
The decompositional perspective towards meaning holds that the meaning of words can be analyzed by defining meaning atoms or primitives, which establish a language of thought. An area of study is the meaning of compounds, another is the study of relations between different linguistic expressions (homonymy, synonymy, antonymy, polysemy, paronyms, hypernymy, hyponymy, meronymy, metonymy, holonymy, exocentric, and endocentric).