I once got a detailed, feedback-driven rejection email, stating very clearly and professionally where I shined in my interview, and where I didn't. I was so app

I once got a detailed, feedback-driven rejection email, stating very clearly and professionally where I shined in my interview, and where I didn't. I was so appreciative of the message that I made sure to follow up with the manager working on my application and thanked them. 9 months later, I found myself in a bad management situation at another company, thinking about looking for another gig when the company that rejected me reached out asking if I'd be willing to come back and interview again. I did and accepted the offer. By giving good and candid feedback, they wound up saving months of searching for a new dev when they reached back out knowing I was a good fit for what they needed at that time. I was essentially a lead they'd already warmed months prior. It made me wonder why more companies don't think of this.