I think those are fair points. I really do give it the "worst RPG I've ever played" award, but as I said, it's not "bad" in a broken sense. It's just boring. Regardless, I too played through the thing start to finish. The mechanics were good enough to keep me going but there just wasn't a lot to do. I can't recall how long it took me to finish it, but it must have been in the 12-15 hour range. 20 hours as an absolute tops. I doubt I could have played it for much longer if it was longer than that.
I also recall that as you could level, you could spam your upgrade points into a one of the attack elemental types and you were quickly OPing everything. I probably kept going trying to max that out. As a kid, I kind of liked grinding in RPGs just so I could decimate everything in my path.
This also might have been my first "action" RPG in a 3D environment. I forgot about that, so there's a chance that it was part of the novelty that kept me going. It's easy to forget details like that as I've aged.