Raggy - Tax Credits are not benefits. They are designed to take account of previous tax allowances that people may have had - e.g. Married couples allowance etc, but pay them in a way that reflects peoples income. There are Credits allowed for those on a low income - a bit like a lower tax threshold and additional benefits to take account of the amount of money paid out by parents for childcare as they try to raise the next generation of taxpayers and still work themselves.
These Credits are designed to help those that do work, not to encourage people to stay on benefits - they are to keep children out of the poverty trap. I could argue all day about some parents using their benefit money and/or tax credits to fund their smoking, drinking, drug and gambling habits instead of spending them where the govenment intended and society as a whole should expect - i.e. on food and clothing and education of children and families. But that has nothing to do with the question here, and I do wonder why you bothered to respond on here.
You seem to be proud of never having to claim benefits, I haven't either, but have claimed my tax credits and I also take my tax free allowance on my salary rather than send extra money to the tax man. However, I have always been both lucky and determined to be in a position to support my family - some people aren't, either a as a result of back luck, poor example or in some cases sheer bone-idolness - you can't however tar everyone with the same brush and I am pretty sure that you take advantage of your own tax free limits in your pay.