Of course, but from my experience that is what people who don't actually drink choose to drink.
Not even hating, I was just surprised a heavy drinker would mix with coke instead of making a legit cocktail or drinking it straight. But I think you should drink it however you enjoy it.
It's just hard to drink that much booze and coke. Just makes sense to drink it straight, especially when you get to certain point of drunkness that you probably can't even discern taste.