If we call abortion murder, we're saying a woman who ends a pregnancy deserves the same punishment as someone who kills an adult. Practically, that means criminalizing women, driving them to dangerous back-alley procedures, and forcing doctors to let patients die rather than intervene. That's a catastrophic consequence we can't ignore.
Ethically, murder requires a person—someone with rights, interests, and standing in a moral community. A fetus is potential life, not an actual person with self-awareness or the capacity to be harmed in the same way. That's why we distinguish abortion from killing a child. It's not a semantic trick; it's the core of moral and legal reasoning.
Even if you believe fetal life is valuable, autonomy and bodily integrity matter. No one should be forced to sustain another life against their will. Murder law protects people. This protects women.