>Some company just expecting free work comes closer to the definition of "entitlement", in my opinion.
If you want a job, you have to put in work. That's just how it is. I too wish companies would just throw job offers at me without me having to put in any effort to get them, but I acknowledge that this just isn't realistic. There is a reasonable upper limit on how much work a company can expect from a candidate, but I do not think a 1 hour presentation is past that limit (and it depends on the job - if I'm interviewing for a warehouse worker job, then no it's not worth preparing a presentation for. but if it's a good job at a good company, then I begrudgingly accept that I've going to have to put in some extra effort). If the OP disagreed, they were free to decline to prepare the presentation and not continue the process. But if you read the OP, they weren't concerned about this "free work" and they actually said they were excited to give the presentation.
I also disagree with the idea in this thread that the company is trying to get "free work" out of the candidate in any way. It's not like the company is going to take your presentation on your random side project and go use it to try and sell services to customers or something. That's fantasy land. After your presentation, your PPT file is going into the recycle bin whether or not you got hired. Trust me, they don't want to sit through your random throwaway presentation either. They just want you to do it to see if you're a worthwhile hire, and then they want it to end. They aren't doing it for "the work".
> the fact that there was a recruiter involved makes it seem to me that they contacted him
Recruiters are involved in all hiring at the companies I've been at, even ones where the candidate applied. "Recruiter" is just the generic term for "HR person who is the point of contact for the candidate during the interview process".