I actually resetted twice. When the game first came out, I just jumped right into it while only looking for a native fruit (which I decided to change later on as well) and not knowing any limitations of the game, I chose a map I couldn't work with. It was mostly the two south river outlets, they took away a lot of space and I can't work well with vertical spaces. The rocks also sucked, but it easy to forget them.
For the second island, I really screwed up the achievements by traveling backwards to cycle villagers out and that really bothered me. Also I wasn't far along into the island and felt no real connection to it, so I had no issue resetting again because I still have a lot of time on my hand. The island itself was alright, had a nice secret beach location but a river flow I didn't prefer, though that barely matters. I welcomed resetting.
Now with my third island, I love it. With flaws and all. I have a starter villager I really love and I already have a higher friendship with him than I had in my previous tries. I transformered a considerable amount of the island, but I worked with what was there and didn't have to terraform for hours. My island doesn't look like anybody else's. It's very basic, or natural depending on how you like to look at it, but I enjoy it. I'm not the kind of person who can make use of every little spot, but I can make myself an enjoyable island that has a lot of thought put into it.
I don't plan on resetting again, but if I do I wouldn't be too hard on myself. I want to enjoy the game in the moment, and sometimes it just doesn't feel right anymore. But I try to not drive myself crazy over my layout, everything could be different but everything has flaws too. I'm just happy I have a nice set of villagers and managed to get some nice recipes and furniture so far. Everything can be changed, I like my rivers and the location of the secret beach doesn't matter too much. I could dislike my town hall position, but it's convenient for me and I can work with it even if Nintendo never adds an option to move it. Terraforming everything can be a sour experience, but it beats resetting after a while.
Overall, I don't regret a single island I played. I have lovely memories from all of them, but I'm confident with my current one. It's all good.