I don't mean to nit pick, but it's seems like the only way to iron this out. "Theft is defined as stealing" isn't right. Rather: theft is defined as stealing property (or services). Property means real possessions in this context, not intangibles like IP.

A person can steal an idea (or market share) and it wouldn't make them a thief.

The fact that a victim of copyright infringement may end up disadvantaged to the exact same extent as if they were a victim of theft does not magically equate the two, even if the two involve stealing.