Politics didn't make taxi medallion expensive, they gave it free, it's supply and demand that made them expensive[1].
Taxi are not useless, not everyone is able to use and app on his smartphone and some people want the simplicity to hail a cab. But the taxi license starts to decrease.
Banning UberPOP is about consumer protection because VTC or taxis are professional that had an exam, special insurance, they pay there taxes, unlike UberPOP which is about transferring the costs on insecure workers and unsustainable jobs that don't take in account of all the costs of doing this job.
[1] : http://fr.wikipedia.org/wiki/Taxis_parisiens#Le_prix_de_la_l...