Here's an interview with a woman who got uber drivers prosecuted: http://www.bbc.co.uk/programmes/b0783lhl
Here's another article about the same woman: http://metro.co.uk/2016/04/19/blind-woman-repeatedly-turned-...
A different case: http://www.bbc.co.uk/news/uk-england-birmingham-30523449
And another: http://metro.co.uk/2011/02/28/blind-yvonne-saint-john-guide-...
Uber is far from unique in refusing service dogs or wheelchairs. It seems the rules are more clearly explained to regulated taxis than they are to less regulated minicabs.
It’s been two years since Uber launched and they still haven’t really taken off, mainly because they are a lot more expensive than the other apps and don’t have as many cars. Although Uber’s cars are a bit nicer (executive car vs 10yo Prius), people here are cost sensitive so that isn’t really a selling point.
And yeah, I'm a Londoner, don't really feel the need for Uber to exist in my area.