Because forcing people to PERSONALLY pay for things they don't want to amounts to slavery and should have never been legally possible. Nothing prevents insurance companies from proving the coverage, nothing prevents employers from providing the coverage, the issue is the mandate.
Now, before you go off on the deep end of bullshit about how companies won't provide it without being forced too, I work for an insurance company and in under an hour, employers and my company had worked out benefits and made the announcement that many plans would offer travel benefits for people needing to travel to get an abortion that includes a care giver as well. So keep at it Leftist crybabies, you are running down the slope of totalitarian oligarchy at break neck speed.