Gotta disagree here. It may depend on your definition of "completed" of course.
Every storyline leads to you "seducing" the character, having the opportunity to have repeat sex with them. Exception Debbie, but there's a chromosomal hindrance you're facing. This is a perfectly valid point for a game like this to consider the storyline finished. Also, you have dedicated "think about the future" endings for all of them to wrap it up.
There are certainly loads of options how to increase content or expand on existing content. There's a couple women left unattended (barista, casino dealer), there's a couple other possible expansion hooks (girl group wanting to come to your city), there's some girls which could IMO use a "single ending" (Sophia, Amy), and not all characters get the same level of development (landlady and roommates of course have more than Pam or the shrink), but nothing of that means "unfinished" to me.