Defining Spontaneous Impulsivity (or why Webster's Dictionary thinks I'm irresponsible and flighty)

Interesting that both definitions are fairly negative (or maybe that's how I read them). Of course, impulsively getting in the car with a stranger bearing candy is a bad decision and in my case I am utterly broke until Friday because of my spontaneous decision about Chicago but I don't regret it for a second! Why is being impulsive and spontaneous considered a bad thing? Is it because society would fall apart if everyone were to do what was fun and inspiring vs. that which is "required"? Sure, jobs = money, money = necessary BUT we get so wrapped up in work and money that we miss so many wonderful things along the way. Of course, we can't always help that and not everyone has a job or the ability to afford being impulsive or stopping to smell the proverbial roses but then again the world isn't always fair. Its hard balancing life, work, altrusitic inclinations, wanting to be successful, make the world a better place, make enough money to see the world and have fun while saving it. Whew. That's a little intense for a Monday morning, especially after the weekend I had- more on that later, for now, here's the defintions:

spon·ta·ne·ous Pronunciation Key (spn-tn-s) adj.

1) Happening or arising without apparent external cause; self-generated.
2) Arising from a natural inclination or impulse and not from external incitement or constraint. 3) Unconstrained and unstudied in manner or behavior.
4) Growing without cultivation or human labor.

im·pul·sive Pronunciation Key (m-plsv) adj.

1) Inclined to act on impulse rather than thought.
2) Motivated by or resulting from impulse: such impulsive acts as hugging strangers; impulsive generosity.
3) Having force or power to impel or incite; forceful.
4) Physics. Acting within brief time intervals. Used especially of a force.