You need some sugar to get it to be soft enough to scoop. Otherwise, no matter how much air you beat into it, it'll be a brick. The sugar forms a syrup that doesn't freeze, and the fat globules become suspended in that syrup, kind of like a matrix. The more sugar, the better the consistancy.
I've experimented with using lower ratios of sugar, and found that the least I can use and still get a respectable texture is 2 tablespoons of sugar (or maple syrup) to 1 qt liquid. I would then use 6 tablespoons of stevia for the rest of the sweetener. If you're making a French (custard) style ice cream, add the stevia after cooking the custard, it'll become bitter if you cook it.
You can find a million recipes online for ice creams, they all fall into one of two catagories. In French, or custard, styles, the milk and cream are cooked with an egg into a custard, then cooled before churning. Philadelphia styles are uncooked and do not contain egg. Both are good, the Philadelphia style is obviously much easier.