100% of course. I've recently finished Clannad, and to be honest played it more than needed xD even replayed some routes, but sometimes because I had to replay in order to unlock more stuff. It took me like 5 months, played Clannad daily, loved it, so I'd felt kinda guilty when I skipped xD But now that I've experienced Clannad, I think other VNs are easier to get by with in order to get it all.
So yes, when I play a VN I play it in its entirety, even the routes with girls I don't like, it happened to me with Yume Miru Kusuri, when I finished it all, I realized I didn't enjoyed it that much