I actually do not agree with tax credits but you are wrong on this point as they are used to top up the wages of low paid workers. It has nothing to do with how hard working you are and everything to do with what type of employment you are in.
I don't know if you aware, but the minimum wage is going up over this parliament to £9ph, plus increases to free child care and the tax free allowance.
Taken together,
these negate the impact of changes to tax credits after next year.
As usual, the facts often get lost when free handouts from the government are cut back.
Note that there was no outcry when:
1) NI went up for higher rate tax payers.
2) Higher rate income tax band reduced.
3) Child benefit withdrawn from higher rate tax payers.
There's something wrong with the system when people can't be bothered to earn more money, if I get a promotion I'll be dragged into a 60% band as the personal allowance is withdrawn, totally not worth taking on the extra responsibilities IMO.