Depends on the pay. If more companies start doing this, then you can imagine having to slog through 10-20 of these as an applicant will increase the time to find a job significantly. Most people don't get hired off of their first successful round of interviews. If the company pays as much as the job salary itself then I am fine with this.

Adding up all the overhead and stuff that comes before and after, we're talking about an interview process that's 3 full work days. That seems a lot, even when you're paying people. People will either have to take days off their job or sacrifice weekends.

I'd expect lots of employed people with families not to have 15 spare hours X the number of companies they are interviewing with