I'd personally rather give the candidate AND the company a chance at hiring a potential candidate than missing out on one. The longterm impact on your company is huge.
There are two kinds of hiring managers- those who think the system works and they're skillfully picking the best talent, though at the last minute, without formal education on the subject, without metrics, without reproducibility, without accountability, and with minimal prep time; and those who recognize the system is deeply flawed and go along to get along.
What would you do, go to the beach, hang out in a bar? So your time would be spent better. Maybe you would go to other interview where you would be hired but you cannot know this in advance.
The same with company they don't know if other candidates would be better until they actually do on-site.
If you can predict future then yes. But most don't.
What's the unemployment rate for top-end talent in Silicon Valley? 2%? 1%? This foolish strategy of candidates-time-is-free is designed to turn off people who already have jobs and want an upgrade. Not only are you _not_ hiring the best, you're limiting your applicant pool to the worst.
<sarcasm>Why, sure, I'll blow 7 hours including 2 hours' roundtrip commute to audition for a 20% chance of a $10k raise.</sarcasm>