Vocabulary and color palettes
For a writer, vocabulary is akin to a color palette for an artist.
You can use pedestrian words like 'good' or 'bad' but there's only so much you can create if that's all you have in your repertoire*.
I think of these commonly used words like the primary colors – important but perhaps a bit uninspired.
Let's add a bit more flavor.
Poor. Terrible. Atrocious. Abysmal.
Auburn. Crimson. Burgundy. Carmine.
Good. Wonderful. Marvelous. Exemplary.
Aquamarine. Cobalt. Cerulean. Turquoise.
Each tweak changes the meaning of a word by a little – enough to impart more flavor, more specificity to the sentence it joins. Just like each shade of color has the same base but communicates slightly different meaning.
*Unless of course you're a master of your craft – then the argument breaks down altogether.