In my opinion, no consideration should be given to 'business interest' over the interests of the workers. The idea that the workers ought to just settle for compromises is rubbish.
Well life is about compromise, so there's that. A 100% pro-worker, anti-employer solution would not work, just like a 100% pro-employer, anti-worker rights solution wouldn't either.
https://en.wikipedia.org/wiki/Eight-hour_day
Keeping this history in mind might allow us to determine other reasons and means for improving on the workweek than pure business interest.