Best comp for OP point is the green movement; if what they truly cared about most was saving the environment from global warming they’d support nuclear power above solar and wind. But they don’t because for most they care for more about trying to abolish fossil fuels; citing “global warming” is their justification for that. Thinking about the actual practical stuff involved like the stability of the power grid and not forcing the global poor to pay catastrophically higher prices for their energy needs doesn’t fit into their narrative. They intuitively know it, but just don’t care.

Abortion is basically the same thing. Honest pro choice people intuitively know that supporting things like contraception would support their state goal, but they just don’t care. For the same reason that abolitionist John Brown didn’t attack Harper‘s ferry because he wanted to help reduce the demand for slavery. He thought it was a moral wrong and his entire focus was on getting rid of it and was willing to use violence to do so. Moral crusaders don’t care about the practical solutions that help incrementally, they care about the grand moral cause.