You can’t just apologize and pretend like it never happened. You have to regret or be sorry for offending God, and you have to work towards not doing it again. A priest
can deny someone absolution if he thinks they will do it again, especially if he thinks they willingly or purposefully will do it again.
Someone I know was divorced, as was her new boyfriend. Though they were in the process of both getting their annullments, the lady went to Confession because she felt guilty for dating the guy. The priest told her she had to stop seeing the guy until both their annulments were complete. She said she couldn’t promise him this, and he told her he wouldn’t absolve her until she did. She wound up going to another priest and getting absolution

but the point is, regarding the fact that you think excommunication doesn’t make senese if you can just apologize, that’s not how it’s supposed to work.
In the case of an abortion, there’s no doubt in my mind some women are truly sorry for the abortion, especially if they
wanted the pregnancy but it had to be terminated to save their own lives. The priest of course would grant absolution, if the person regretted the action, and if the person doesn’t intend to do it again.
Face it people, everyone sins. We’re human. If we had no way to be absolved for sins, we’d all be in Hell, even the “pro-life” people. Absolution and reconciliation gives one a chance to make things right, when we’ve done wrong.