The issue is one is expected to fork out his full responsibility for a decision he had no choice over (to keep the baby) but there is no such responsibity on the other party, ie. mum has no expectation to be financially responsible for the child and made to work to support them
Tell me, how many mums do you know that take no financial responsibility for their children following the breakdown of a relationship? Because the statistics show that by far the majority of single parents work.
A decision to have sex is to understand that there may be unintended consequences to that act. You consent to that implicitly, understanding that an abortion may not be an option and that you will pay for that consequence for the rest of your life. If those consequences are not something you can cope with, you simply don’t have sex. Not rocket science, is it?
And tell me, what of men who have children in long relationships and marriages who then decide it’s not for them. What of those men? Do they also get the right to walk away because they changed their mind?