Parlez-Vous Français?

For the Francophiles among ye, I have a very basic question...

Why the fuck doesn't the French language differentiate between the simple present tense and the present progressive?

Isn't there a difference between the statement "I work," meaning, "Yes, I am nominally employed," and "I am working," meaning, "Leave me alone kid, I'm busy?" Is this how they get away with a 35-hour work week?

Just asking.