Taxes do unjustly (sexism, dick tax) punish single men, but the marriage deal is even more disadvantageous. Most marriages will end in divorce, and most divorces will end up very unfavorably for men.
Thus avoiding marriage stands to reason.
There should not be a legal concept of marriage to begin with. The state should just treat everybody as individuals, and end this anachronistic insanity.
Unfortunately biology doesn't treat everyone as equals. Women most often end up with the burden of raising the children. Marriage has a lot to do with making a commitment to stick around and help raise the kids.
Once the child is past the age of breast feeding, biology has nothing to do with how well you can raise a child. It might determine who ends up with the child since judges tend to favor women, but that has more to do with tradition than their innate parental expertise.
Married or not, you can decide to take off at any time. And married or not, a man may be forced to pay for a kids - even if it's not his biological kid.
Please don't pretend that mothers and mothers-to-be don't have any agency in the events that lead up to birth. Marriage has little to do with reproduction. It's a legal construct, not a natural one. The law should not be obligated to compensate for the edicts of biology and certainly not at the expense of another's economic freedom. A woman chooses to incubate, and raise children. Where coercion or duress are not involved, she should bear responsibility for what are all the consequences of her choices with regards to her body.
Thus avoiding marriage stands to reason.
There should not be a legal concept of marriage to begin with. The state should just treat everybody as individuals, and end this anachronistic insanity.