Perhaps because there is no consensus that those drugs induce an "abortion", outside of catholic circles and the folks that insist that it is a person once sperm collides with egg? You're referring to Plan B, are you not? Or did you mean the birth control pill, since some also consider those to be a form of abortion?
The reason that people villainize hobby lobby is that they take the insulting stance of not trusting their own employees to do what is right and moral according to their own morals, and they want to enforce their own religious views upon the private lives of those employees. They don't know that any of their employees are doing any such thing, but they made a big deal about it being even possible, and want to create an option where they can take the power to make those decisions out of the hands of their employees.
Paying for health insurance that also covers abortion and birth control is no more guilt-inducing in the employer than paying your taxes makes the taxpayer guilty of murders committed by the bad apples in our military overseas.