EDIT: It appears I was wrong. Original comment:

Uber is by definition a side gig. Nobody is doing Uber on the side in their 1989 LeBaron. You need a nice car, and you can't get a nice car if you only income is from Uber.

Not that I'm defending the comment you replied to, but your comment is simply untrue. Uber even partners with auto loan companies to provide leases to their drivers. You can absolutely survive 100% on just Uber income. Many do.

Indeed, that's why classifying sharing economy workers as 1099's is not right. Some people rideshare as a side gig, but others do it full time. There ought to be a new classification to account for that range.

Whether you earn your sole income from an activity or not has no bearing on whether you are an employee or a contractor. It's a tax decision based on the employer's relationship to you.

What percentage of Uber drivers are able to support themselves above the federal poverty line driving for Uber alone?

They've claimed that those driving during busy hours in high-demand cities (with good potential of surge pricing) are faring fairly well http://newsroom.uber.com/2014/05/an-uber-impact-20000-jobs-c...

And that's just UberX. UberBlack and UberXL have higher revenues, but require higher upfront investments as well.

An unprofitable side gig is still a side gig.

Well it depends 100% on how you "account for their time", now, doesn't it?

If you value their time at $0/hour, they're all coming out ahead over a long enough time horizon barring some freakishly bad luck with car repairs.

At $1000/hour, none of them are coming out ahead.