Why even reach out if I'm not what you're looking for?

This company reached out to me last week (these emails are all from their side, I've omitted mine for privacy reasons). I'm a designer and I'm aware that my portfolio is not up to date, because I'm not looking for a job. But thought hey, this could be a cool opportunity. They then rejected me over email because my skills "weren't up to their design bar."

My question is...why even reach out?