How many times does it happen when we read a text we are able to relate to it? We want to read more and more of it. Simply because things get into our head with so much ease and so much simplicity.
But sometimes, exactly opposite of this happens. We fall in a situation, wherein we do not know as to what is wrong with the text, but we try hard to pick it up, and again get either bored of it or feel confused because of extreme verbosity used by the author in the text.
All this happens due to the interplay of vocabulary. Right vocabulary means the use of correct words - not too less and not too much. Now that does not mean that words should be balanced before using, but definitely, there has to be some measure, quality, and temperance which will help the author in predetermining the interests of the supposed readers.
Some people feel that using unique and archaic words is good as it helps in increasing the overall attention of the user, thereby also helps the overall reach of the text. But, then these people fail to realize that flowery words do not matter as much as the feeling one gets upon reading a text.
Thus, writers should use 'Familiar style', as discussed by William Hazlitt in his essay "On Familiar Style", which is not about using pedantic, showy, lengthy words. But using impressive, easy to relate to vocabulary.