Probably a majority of the people who pirate products would never buy, but in a market where 500 sales is considered a successful release, even if 10% of the people who do pirate would buy stuff it could almost double the sales, and as such you would have more venders who could activly make products.

It does take alot of time and effort to make a product, and when it is pirated within hours of release it really does make you wonder why you even bother.