Well I guess the question is: if desperate people might take the job, and the job is not sustainable for anyone but teenagers and retirees, should the job be allowed to exist seeing as it would not sustain the desperate person?
my answer might reveal a philosophical difference between our points of view, but I'd ask: would the desperate person be better with a job that covers some of their expenses or no job that coverers none of their expenses? I believe in having a social safety net of some kind (i really like negative income tax), but how useful is it for the government to ban jobs people would otherwise work?
the argument could be made that uber could just be forced to pay a living wage, instead of banning their jobs- but the difference is small. uber is already losing money- i would say that forcing them to pay a "living wage" just hastens their collapse and bankruptcy, so we're back to arguing if these jobs are better existing or not existing.