The whole system is fair too easily manipulated.
In reality the number of men "tricked" into becoming fathers is tiny. Those this happens to need to think about their attitude towards birth control.
The vast majority of those (predominantly men) who fail to pay any child support are those who left (or were asked to leave) relationships where children were planned.
The idea that "contact" and payment are balancing factors is simply a power play.
Decent fathers don't get into arguments about this matter. They pay what they can afford (including over the mandatory amount) often without any intervention from the CSA. They do this because they take parental responsibility seriously and have no interest in making their children suffer as a way of sticking two fingers up to their ex or through the sheer selfishness of wanting to maintain their lifestyle at any price.
It's still far too easy for those who own businesses to manipulate their finances to earn very little whilst enjoying the benefit of a very lavish lifestyle. Equally true were the new partner owns a business and "employs" the ex on a minimum wage to do a senior job whilst then using the company profits in their name to fund an extremely comfortable existence.
Of course this leads to bad feeling and the manipulation is so obvious (for example a friend struggling to pay for a school uniform where the ex lives in a million pound property who when the child visits then offers to pay for trainers worth £££ but won't pay maintenance) that the children themselves see it and understandably feel angry at that parent. They don't want to have their noses rubbed in it when visiting - seeing half siblings in designer gear whilst they arrive in clothes from a charity shop. Contact falters.
There's the fathers who don't really want contact anyway - cramps their style so whilst arguing for it at every opportunity, make it incredibly difficult to facilitate (changing date/times, often at he last minute, placing restrictions on contact and drop off/collection). But hey - they can then say I've only seen my child 3 times this year I'm going to cut payment even though they have deliberately manipulated the situation to be that way.
A child and their needs don't disappear because a father doesn't see them.
However I will also balance this by saying I equally find it abhorrent when resident parents use (withdrawal or manipulation of) contact to increase payments over what has been agreed (for example if you don't pay for a summer holiday for me and child you don't get to see them all summer).