Thanks Brooksy and PrivateBryan :)
I have learnt a lot from what Verbier_Ski, SwingBeep and the others have said - thank you very much :)
But I still think there is a lot more to understand about this. I don't think the ESF or the French government really think ski hosting is dangerous, but clearly there are other problems connected with it, like the issue of ski hosts being paid below the minimum wage, which breaks the law.
I found this, on the ESF Facebook page, which is a French newspaper account of the case.
This is a description of the Smic (French minimum wage standard):
The Minimum Interprofessional Growth Salary (SMIC) sets the minimum hourly wage in France (metropolitan area, overseas departments and overseas collectivities of Saint-Barthélémy, Saint-Martin and Saint-Pierre-et-Miquelon). An employer may not pay an employee less than this amount set by the Government and risk incurring penalties if they do so, and this regardless of the form in which wages are paid. Since 1 January 2011, the amount has been set at 9 Euros per hour gross, or 1 365Euros per month net, based on a working week of 35 hours. A reduced rate can be applied in certain cases, particularly for apprentices. The SMIC is automatically re-evaluated on 1 January every year. It can also be re-evaluated in the case of an increase in the consumer price index exceeding 2%.
http://www.france.fr/en/working/ins-and-outs-employment/professional-relations/all-about-smic