It really isn't as simple as saying "everyone should work less hours" (I hate the term "shorter hours" they're all 60 minutes long, no matter how many you work).
The public expects shops to be open, businesses expect other businesses to work the same hours.
In order for companies to provide the same levels of service staff will have to work different hours - some doing 9-4, others doing 10-5, 11-6 etc.
The other option is for businesses to operate for fewer hours.
From experience of dealing with French companies, I would assume they use the second model, because they're the most inflexible people I've ever come across - orders to be placed by 10am, no orders can be placed on Fridays, 16 public holidays a year, and no-one works the holidays.
We either have a system with high levels of service, or we have a so-called European model. I can't see a way to have both without a seismic shift in peoples working patterns.