Many people consider etiquette to be a stodgy practice, rife with ridiculous, impractical, outdated rules. When one learns the motives behind manners such an attitude usually evaporates. The social graces are intended to make people comfortable and prevent spills, knocking over fragile crystal glasses, et cetera. They have nothing to do with snobbery or elitism.
Same goes for the basic rules of grammar.
They are in no way meant to create a schism between writer and reader, but rather are tools designed to gently lead the reader in the direction the writer desires.
Commas, especially, can be a tricky business—at least for me they are.
For people like me, GrammarBook.com comes to the rescue with the following directives:
Commas and periods are the most frequently used punctuation marks. Commas customarily indicate a brief pause; they're not as final as periods.