The article; http://www.tdg.ch/geneve/actu-genevo...story/25706983
Says that new law is specifically aimed at Segway and motorised single wheels.
Here is a translation of the most pertinent paragraph;
"Jusqu’à il y a quelques mois, un flou législatif entourait l’utilisation de ces engins. Mais depuis le 1er juin, l’Office fédéral des routes (Ofrou) a décidé de cantonner ces monoroues et leur cousin à deux roues, le Segway, aux routes et aux pistes cyclables. Terminé le slalom sur les trottoirs et les zones piétonnes".
="Up until a few months ago a there was a grey area around the use of these objects. But since the 1st of June the Federal office for Roads (OFROU) has decided do push mono-wheels and their two-wheeled cousin the Segway onto the roads and cycle paths. Finished the slaloming on paths and in piedestrian zones".
A motorised vehicle of any sort capable of over 20 kilometres an hour (not
10 as you cite) is a menace on a crowded pavement, with a lot of riders expected pedestrians to give way to them;assuming they have priority because they're simply faster.
If those riders had been less pushy in the first place a new rule might not have been considered necessary.
I agree that a busy main road is maybe not the ideal place for them, but I see no reason at all why they shouldn't be using the ton of cycle paths around.