Are you finished having babies? Really?

Now that I'm pregnant (again, lol), I find myself watching all the pregnant/baby shows on tv. The current one is about a couple that are expecting their 3rd child, but ONLY wanted 2 kids. They used fertility meds for the first two, so thought they didn't need birth control. It just boggles my mind that a couple would be "finished" and not take steps to be sure. So the question is, why do people not get 1 (or both) partners sterilized if they are so very adamant about not having more kids? I've heard from so many women that they just plan to use birth control for the next 15-20 years until menopause. Wouldn't a tubal or vasectomy be the best option, especially if its covered by their insurance? My husband is getting a vasectomy after our 4th (we don't like to be surprised!). What are your plans?