Disclaimer: I work for Uber and I'm brazilian. Opinions are my own, etc.
What the GP is criticizing is that they see this as a power move to increase government income through taxes. The underbrush is that this money is then stolen by corrupt government officials (it's common perception in brazil that that's just the way the brazilian government works).
In this light, Uber is just the sucker-du-jour who gets to be "screwed over" in the latest corruption ploy.
Uber's perspective in this type of matter is that there are a large number of drivers who don't do ridesharing full time or even on a consistent part time basis (for example, one's free to do it once or twice ever). An apt comparison might be someone who sells stuff on craigslist - yes you can do it full time, but people often do it for just extra cash, without considering it a "job" per se. So you can see why Uber might not like to restrict driving opportunities only to those who are willing to commit to a full-time employment arrangement.
With all this said, I'm all for having drivers who are effectively working full time hours to be able to earn a reasonable income. I'm not too familiar w/ the state of lobbying in Brazil, but my understanding is that Uber is going to be lobbying in the US for a third employment category and one of the talking points of that proposal is to work towards income improvements for drivers. The position that drivers are not employees goes both ways: if they are considered Uber's clients, it behooves that Uber should do its darn best to provide the platform with the best payouts in the industry, lest drivers would flock to a better paying competitor.