You could look at this another way: you are trying out the company, and they are paying you to try them out.

A few hour interview may not tell you much about the candidate, but as the candidate, it doesn't tell you much about the company either. The future boss/colleagues could appear pleasant for the hour you get with each of them, but could be real jerks when you actually work with them. Maybe they just have a different style of work than what you prefer. Or maybe they said "agile" when you asked them, but they are anything but. I could go on.

For me, I really like companies that hire this way because it also allows me to try out what it's like to really work at that company. And get paid to do it. No one wants to be the guy who quits after 2 weeks coz the job sucks.