No one should die from smoking (they especially shouldn’t be forced to die) but while i doubt your dad is this kind of person, many people who go out smoking truly don’t make any kind of effort to quit and they are truly bad people.
You seem like you're posting in earnest, so I'll try to meet you where you're at. For what it's worth, I find smoking viscerally disgusting, so I am somewhat sympathetic. I genuinely cannot stand being around people who are smoking, and I figure the world would be a million times better without tobacco in particular. So I get it.
Saying that people who smoke and don't try to quit are "bad people" is just deeply cruel. Saying that someone is a bad person is one of the harshest moral judgments you can make about them, not something to throw out because you think they're making a bad decision. Everybody makes bad decisions -- some more than others, but nobody gets through life without fucking up a lot. That doesn't mean everyone is a bad person.
Why does smoking make someone bad? Is it because they're hurting themselves for no benefit? I doubt that's what you mean, just because it's kind of a weird position. Eating french fries is bad for you, but I've never heard anyone say that you're a bad person if you go to Five Guys and order a 5,000 calorie bag of fries. Sure, they taste good, but lots of people who smoke like the way smoking feels, too.
So I guess the idea is that smoking is bad for other people. Which is true. Being a non smoker around people who smoke sucks and is bad for you longterm. But again, everyone does things that are bad for the world longterm. You buy products that have more plastic than they strictly need to. You support businesses that directly and indirectly hurt people. I guarantee that manufacturing whatever device you're posting on involved copious child labor. Does that make you a bad person? You can argue that your computer would have been built anyway, but you chose to give money to the business that built it. And yeah, if you want to live a "normal" life, you have to engage with these aspects of society, but you don't
really have to. You could go live off the grid, but you don't. I don't think that makes you a bad person, but only for the same reasons I don't think people who smoke are bad for doing it.
Obviously it's easier to not start smoking than it is to opt out of modern society. But starting smoking is a single decision people make, usually at a young age. Once you start, it's genuinely very hard to quit. Your lifelong moral worth is not determined by a mistake you make in high school.