Exactly. Piracy extends the commercial ecosystem. Every software pirate is a potential user and contributor of FOSS projects who is instead spending their time and talents working on/with commercial offerings.

To a distributor of commercial software, a pirate user is preferable to a user of a competing product. The competing user is already locked into the competition's product line; the pirate is expanding your own product line's market share.

Below the competing user is the FOSS user: it is much easier to monetize a pirate user who likes the system enough to steal it, or a competing user who has demonstrated they are willing to throw money at their problems. FOSS users aren't willing to tolerate all the artificial limitations imposed on the product to increase profitability.

I have no moral or ethical qualms with piracy as a general concept, but software piracy inherently promotes commercial alternatives at the expense of FOSS products. The only software I have pirated in decades has been rare, niche software for very specific uses.