I planned to TT, and I did. Remember- there's literally no way to "win" Animal Crossing. And, since it's a single player game, "cheating" is entirely self-defined. If you don't want to time travel, you don't have to. But it's certainly not a moral failing if you do, and it's certainly not "bad". Like, I read some people consider using fast travel in Skyrim to be "cheating" since you should be walking instead. But it's not wrong if you don't. And if you save before doing something in a single player game, in case it doesn't work, again... not an issue. As long as no one else is getting hurt, it doesn't matter.
I mean, for me, TTing has been an important aspect since the very first game. I did, my friends did it, my family who played did it. We all TTed. I was in college when I was talking to a girl and she was like, "Don't judge me, but I time travel." and I remember thinking, "Wait, doesn't everyone?" and I was shocked that not only do some people not do, but some people JUDGE others for doing it! As if there's some weird way to play a single player game more "ethically"? Yah, I've just never understood it. I mean, some people don't travel because they don't enjoy it and want a more leisurely pace- and that's cool! But I tend to play games in bursts- I play one game obsessively for a week or two, then move on to the next (though I usually do 1-3 games at a time). So I TT because it works best with my play style.
So, yah, bottom line is: you can't really "cheat" in single player games unless you decide to define something as cheating. I mostly played CF by TTing between holidays and selling the furniture. It wasn't how it was intended to be played, but I absolutely loved it and had a blast with it. And I remember abusing an item copying glitch in Pokemon Emerald to get really awesome Pokemon. I played by myself, but it gave me a shot at some of the end game battles, and it was some of the most fun I've ever had in a Pokemon game! I'm glad, in those cases, I didn't listen to others telling me it was "wrong" or "bad" and just did what I wanted. As long as no one's getting hurt, there's no harm in playing a game how YOU want.