jno, I think you have missed the point totally.
The idea is that to claim benefits you should have paid into the system for a short while, say two years.
1) This helps pay for whatever is to come and
2) it stops migrants coming solely to claim benefits (and never work).
This is no different to many insurances, particularly health and employment, where a certain time must pass before you can claim on all benefits of the policy.
Of course, you may be happy to pay your taxes (do you pay any) to all and sundry and you are entitled to that opinion, perhaps if we adopted the two year policy you and your right-on mates could continue paying the migrants whist those of us who prefer not to dont?