But that still leaves the certification of the vehicle, and with the number of kms taxis drive that's not a luxury. Your regular TUV checkups are targeted at regular drivers, not professional drivers. Your insurance company also won't like it if you start ferrying people around on a 150K km/year plan when paying for the statistical chance of getting in an accident based on 40K km/year.
In all these cases Uber drivers are using rules and regulations (and statistics) applicable to personal transportation and applying those towards a business.
And here we get to the heart of the matter: Individual or group responsibility. Everyone is responsible for their own insurance. Every individual has to communicate an estimate of the miles/km they plan to drive in a year to receive a correct insurance. If you fail to do so, you will loose your insurance. No need to regulate this extra and above the systems already in place. As for yearly or 2-yearly checkups of the car, both are also tied to usage. Most people will drive in and around the city, not accross the country. (This is also why Rand has a place in this discussion promoting the über-individual. I also don't always agree with her conclusions but she did address a lot of concerns of her time, half a century ago).
At a guess, insurance companies and passengers alike are not in a position to verify all these issues when they sign up / catch a ride. So some laws were passed and Uber is now ignoring those laws.
That private individuals can lie on their application forms and skip certain tests that are required is not a businessmodel.
In all these cases Uber drivers are using rules and regulations (and statistics) applicable to personal transportation and applying those towards a business.