It's a good question, and one to which I have several answers.
The minor ones are easy: he's pretty lazy, he pursues his own business interests in Parliament while never declaring them, he makes false statements in the House of Commons, he's unreflective and unoriginal, he always plays the victim and he lacks empathy.
But the major reason why I think Paul Uppal is unfit to be a public representative is that I am ashamed that this city's MP is so unintelligent. When I was young, I assumed that all legislators were clever, forward-thinking and incisive. Even the ones with whom I disagreed. But as I get older, I acquire the experience and knowledge to assess these people with a cold eye.
I'm not the sharpest chisel in the tool-box, but I get by. I cling to the idea that if someone has power, they should be cleverer than me, and I don't think that's unreasonable. But in Uppal, we have a prime example of the structural corruption of politics. Rather than independence of mind and intellectual freedom, we have in him a man who combines slavish devotion to his political masters with a degree of ratlike cunning which might - at first glance - seem to be intelligence but is instead simply ruthless ambition. Peruse his record: what you get from his speeches is the unreflecting repetition of two themes: a) that commercial property taxes are evil and oppressive (Paul's a commercial property speculator) and b) that if he's succeeded in life, everybody else must be able to unless they're total wastrels.
What's entirely lacking is engagement with reality. He has a fixed ideological position (until his superiors want him to believe something else). Other MPs of all sides develop weird interests or odd points of view because they're too bright to be treated as machines. Some of them become figures of fun, others distinguished and doughty defenders of noble causes.
I'm sad to say that Mr Uppal hasn't the intellectual or personal resources to take either of these routes. He is, simply, the mediocre multimillionaire, and this city deserves better.