You mentioned "if Uber wants full time drivers they should give incentives " however Uber does not WANT nor need fullfime drivers. As you mentioned, their model employee is people who want to supplement their income or work towards goals and use it to help them achieve that goal.
Also people who work full time for Uber who are complaining that they aren't paid enough should realize a few things and be thankful they even have this option to make a little a money at all.
Before Uber for someone to drive a cab they either had to rent a cab and pay around 100 dollars a day to the person who owned the cab medallion, or they would have had to buy their own medallion and permits to be allowed to work at the airport. The total cost of to own their own cab in most populous cities use to cost about $200k.
Uber blitzed the markets around the US almost overnight. And over night those cab medallions ended up becoming worthless. Uber made billion dollar deals with cities , basically bribing the city council to let them operate in that city.
Did the cab owners get any piece of that money ? Even a dollar of it? Nope they got screwed over bigtime and ended up losing 200k just like that.
Source: my father has been a cab driver for 32 years , with his own medallion and permit and not only is his cab medallion and airport permit basically worthless now but the transpiration business is oversaturaterated in all markets meaning he makes half if not less than what he use to make. Luckily my dad bought his cab business in the 80s where the permits were only a few K and is pretty much at retirement age and doesn't have to support a family any longer
However I do feel bad for the person who likely saved up for years or took out a loan in 2010 to get their own cab medallion, who has a family to support only to have it be a 200k loss because of Uber