Resetting can be a breath of fresh air, but I could never do it either!~ I just love my villagers too much, the same thing with my town. When I actually do want to reset, I usually just end up getting another cartridge, maybe that's why I have about four copies of ACNL haha.
I would love to reset my town... but I've had it for years... Nnnnnnnngh..... So much progress has been made, so I can't reset no matter how badly I want to.
I've reset more than once before, though usually it's on undeveloped towns. I did reset a town a put a ton of work into, and I've missed it a lot since then. But, I reset due to losing several of my favorite villagers after a brief hiatus, and silly as it may sound that alone made me unhappy with the town. There were other factors, too, layout aspects that finally encouraged me to do it- if you're not happy, why bother, right?
Anyway, since I made a new town that I've put equal amount of work into as the old one. It's not finished yet, and I recently found myself in the same position as before: three of my villagers moved. I have two copies of the game, though my second copy was always for cycling (I'm turning it into a real town now). I briefly debated resetting the developed town, but have decided against it. So much work went into it, and though i lost three lovely villagers, I gained a new one that I adore, and another moved into the exact spot one of my prior villagers lived in, which is extremely convenient for me. So I'm going to stick it out c:
I respect players who have never reset, though! I wish I'd kept my original towns all along.