"Plan the same trip" doesn't make sense. I would suggest rewording that. (Maybe "trip sharing" or "itinerary sharing"? Or even "duffel sharing"?) I had enough trouble figuring out what the site does that I went to the About page (and still don't feel I got the answers I was looking for -- like "why is it called duffel?"). On that page, I would reword the "for travelers and non-travelers". It's an artificial demarcation and I don't think it's what you really want/intend to convey. Those folks who would see themselves as "non-travelers" are not going to appreciate the idea that using the site implies they are letting themselves get talked into a future trip. Consider finding a way to package it as "virtual trips" (or "virtual travelers") or something -- to make it clear that you can use the site to collect info on a place of interest even if you aren't actively planning a trip there without implying that use of the site is intent to someday actually go there. It's perhaps splitting hairs but I know that the wording is a turn-off for me and doesn't inspire me to consider using the site to simply collect info about cool places of interest.
I am thinking back in high school or college, in some French class, I did a "virtual trip to Paris" as an assignment. This was pre-internet and it involved collecting maps and things. A virtual trip can have value in itself without going anywhere. I don't travel much, though I have moved around a lot (former military wife). The whole "vacation" mentality is something I have never been able to wrap my brain around. I like moving someplace new and living there for a couple of years but the idea of going someplace for a week or two just makes me cross-eyed. I don't get it. So you are completely missing the mark for me as an individual. If you are trying to convince me that your site has some place in my life, the site fails to convey that -- even though with analyzing it for purposes of giving you feedback, it seems obvious I could probably still use the site for planning to move somewhere or just collect info about places of interest.
And, yes, I have made many trips -- gone on vacations with family (planned by relatives, not me) and visited relatives and hit national landmarks en route to new duty stations and so on. I actually have a life and get around at times but my mental model for that doesn't sync up at all with the way the site presents the idea. So my guess is that if your intent (with talking about "for non-travelers") is to give it broad appeal and pull in people like me, you need to work on that. I don't see myself as a "non-traveler". Nor do I see myself as a "traveler". You have completely failed to convey why I should use the site and presented the info in a way that makes me think "eh, nice but of zero relevance to my life...moving on". If it weren't for the act of trying to give you feedback on it on HN, I would likely completely forget the site and there would be no hope of getting me signed up.
Edit: I will add that my ex and I used to do day trips a lot and those were planned. No hotels were involved. We would go do touristy stuff that was close enough to where we lived that we could drive there, do the touristy thing and go back to sleep in our own beds. (Since we were a military family and moved a lot, we would make a list of things to see and do when we got to a new duty station and try to hit as many of them as we could before life took us elsewhere.) Your site just screams to me "this is for people with lots more money than I ever had who will be staying in a hotel someplace exotic for a week or more -- that's totally not me". Day trips can be very rewarding, can involve planning, and are not remotely suggested by anything on the site.
Best of luck.