To say that abortions lead to less customers or similar statements ie. to say that it's partially responsible for an aging population is not to explicitly make the argument that women shouldn't be allowed to have abortions or be forced to carry pregnancies. It's a possibly implied argument, but on it's own it's just a fact. And without further context her reply could very well be a strawman-argument.
For example one might be against economic situations that make people consider to have abortions (having children being too expensive) and implementing policies that make it cheaper to raise children could be one way to reduce abortions without making them illegal.
I agree. When we have state sanctioned baby murder it is irreverent to the situtation to bring the performance of a business into any of it.