As your second part notes, corporations do indeed often change laws. Laws and reality go hand-in-hand, both ways. Many laws change because they're not working well, to include offending a politician's bigger donors. Companies are a major part of politics, regardless of our preferences.
The bottom line that the UK drivers wanted to have a cake and eat it, bit the hand that feeds them, etc. If Uber lets this slide, it creates a bad precedent for them.
There's been a trend in our society the last 30 years or so that paints a picture of everyone who does manual labor for a living as being a lesser person, and it's damaging us. Yes, automation will save us from a lot of our current burdens but we're not there yet, and until we are we still need people to unclog our drains, pave our streets and maintain the sewers. It's not glamorous and not skilled but it is desperately needed, and we can't just say "well low wages come with shitty jobs" and walk away like not having garbagemen is an option.