You have absolutely no evidence that anyone has 'fiddled' anything. so please don't make such sweeping statements.
The people who sit in parliament do not live on a different planet at all - many of them come from perfectly ordinary backgrounds, and in the last have 'struggled to get by' along with the rest of us. This idea that Members of parliament don't understand what real life is about is a fallacy - they probably see more of real life in their daily mail sacks and constituency surgeries than you do. They have families and mortgages like millions of other people, and as I have repeatedly said, they are just as capable of making mistakes as you and I.
There's a general perception that MPs somehow have an easy life, but I can assure you that the opposite is true. I know two House of Commons researchers, and what they tell me of their MPs' working lives (both Conservative) is enough to make me sure that I wouldn't swap places with them under any circumstances.
We pick our MPs from the people who present themselves for election, and if we're not happy with what we get perhaps we should concentrate on making the job a little more rewarding - then we might attract a higher standard of candidate.