I don't think anyone "has" to be that person, they just choose to be.
That might sound really peculiar, because no one wakes up one day and says 'I really want to die alone that's what I choose to do' right?
But what people forget is that every day they make many, many choices. And if they are unhealthy choices, they can slowly, almost imperceptibly, turn into the person they don't want to be.
The good news is that a little self reflection, a little good intention and a lot of conscious effort can reverse years worth of bad choices. So if you decide today not to be that person, and stick to that decision, then you won't be. :)