Here's why:
* Gerunds are verb forms ending in "-ing" that function as nouns. For example: "Swimming is my favorite activity."
* "Including" is a preposition. It introduces a phrase that provides additional information, often listing items or concepts.
Example:
* "The team, including the coach, celebrated the victory."
In this sentence, "including" acts as a preposition connecting the noun phrase "the team" to the noun phrase "the coach." It does not function as a noun like a gerund.