No, it doesn't.
Jack fights the good fight with honor and a righteous heart. He wouldn't throw away someone's life just for a chance to get what he wants because "Welp, they gonna die anyway when I kill Aku and change the world". It's shown from the start that he wont stand by and do nothing when innocent people are being attacked. you can hold two truths in your heart. You can very well not care if people you don't know exist or not if it's for the greater good in one hand and still not be willing to stand by and watch them get abused in front of you in the other.
It's also shown that there are many time portals and Jack has more than one chance to find one. That's why it's important to notice how Jack fucking snaps when Aku takes the LAST PORTAL from him. He is fucking pissed off at not only Aku but himself because he had so many chances to take a ride home and he's been stuck there for years. His rage leads to him killing innocents in a "I don't give a fuck anymore" outburst.
Also, even though WE have seen and grown to love this world he's in, Jack hasn't. Look at him, he's a fucking mess. He HAS NO FRIENDS.
Sure, he inspires people and is loved by all he saves from the evil that is Aku ... but he doesn't see them again. The only one he might call a friend he had only seen a hand full of times 50 years ago. He's living in some kinda version of hell, where evil controls all and even though he can show people that good, decent things are still in the world it doesn't matter, everything is already corrupted and the evil is too great. Earth is swarming with trash from outterspace looking to do harm to innocent beings even without AKu. Hell, he's never even loved someone in that world til Ashi.
Which was part of the reason for her to be in the story. To give him someone to miss when the world was reset. Hell, SHE was the one to take him to the past in what was one of the best "no duhh" moments I've seen. He didn't show any remorse until she was gone.