Uber has 'demand' because they're advertising. Because they're handing out credits. Because they're claiming they're cheaper (but are they?). Because they may actually be cheaper on selected routes (but not when it matters). Because they may even be operating at a loss until they cornered the market (or go bust).
That's not sustainable. I knew self-employed taxi drivers and they weren't exactly rich, far from it. Having to give some leech 20% of their income would have ruined them, so Uber's presence in their business model must be to the detriment of someone.
So if they survive and corner the market, they'll raise prices (all those VCs want a return, after all). If they don't, they may leave behind ruins where there was infrastructure - no interest in that. There is no option 3, since their business model is fundamentally 'us vs them': Serving all the good inner city and airport routes, while leaving the non-profitable stuff to someone else doesn't work for long.
I can understand that Uber doesn't want to plan for the long term: They might not be around in 3 years, and even if they are, any mess they create here doesn't affect them.
I'd prefer infrastructure to still work in 15 years, and Uber doesn't look like an ally for that cause. In fact their conduct indicates to me that they wouldn't hesitate to burn down society as long as they can instate themselves as rent keeper and make a buck on the remains. Why should I support that?
Nobody forces Uber to enter the German market. If they can't rethink taxis legally, they should leave the field to those who are capable of that (to those who want to: PBefG §2(7) might be of interest).
tl;dr: don't buy taxi services on society's credit card - since I believe Uber customers are doing that when they get 'cheaper' service, any restriction on Uber is a good thing in my book.