The difference is focus.
Scattershot gardeners like all kinds of plants and flowers. They are likely to buy a plant they've never heard of because they saw it, liked it, and immediately felt they could not possibly have a garden without it.
Scattershot gardeners grow a little of everything in their gardens. They plant whatever strikes their fancy.
Every once in a while, someone will become a bullseye gardener. Bullseye gardeners focus in on one particular type of plant and spend most of their time and money on plants of that type. Maybe it is roses. Or daylilies. Or venus flytraps. Almost to the exclusion of all other plants, the bullseye gardeners have only these plants in their sight.
Scattershot gardeners tend to know a little about a lot of gardening. Bullseye gardeners often have deep knowledge of whatever it is they are focusing on.
Of course, many of us are a little of both types of gardeners. We are all scattershot, hit or miss, and then every once in a while, we hit the bullseye of a plant that strikes our fancy more than others so we briefly pause and focus in on that one particular genus. But our focus doesn't last all that long. Another flower comes along, a leave flutters in front of us, our attention is diverted, and we are on to the next plant.
I admire both types of gardeners, scattershot gardeners and bullseye gardeners, and all the variations in between.