Many people absolutely do believe that abortion is state-sanctioned murder and in fact there have been terror attacks against providers [1]. The ones that aren’t carrying out terrorism like this still believe that clinics and doctors are complicit in murder, they’re just smart enough to know that reacting with violence would not work to their benefit and/or just aren’t unhinged enough to do it.

[1] https://en.m.wikipedia.org/wiki/Anti-abortion_violence