Plain is the most boring flavor. Or, rather, it’s a complete lack of flavor. Nobody—or near as dammit—starts out wanting to make their thing in plain (i.e., flavorless). We want flash, darkness, vibrancy, intensity, pizzazz, orange pekoe. But it’s eminently valuable to start out plain and work from there.
The bare bones can be stark or even boring to look at on their own. But the bones are the structure that hold the thing upright, and allow movement and expression. With a solid, plain base to work from, everything else gets easier to add and to tweak.
For many years, I’ve kept to using plain text as a basic unit of writing format. It works on pretty much any platform and can be imported to just about any program or app. Plain is flexibility as well as simplicity. If we think of it as a starting point, a universe of startling and unusual flavors can be chosen to augment it, and even changed if it isn’t as tasty as we thought.
And for the record, vanilla isn’t a default or synonym for plain. It is, verily, the finest of the flavors.