It really depends on one's goals and which MBA program is (respected) by the perspective employer.
I know some people who only went into a Masters program to avoid the start of paying back their student loans.
At the end of the day companies are looking for candidates whom they believe will help them get to next level.
A resume that demonstrates this person has increased sales a certain percentage, improved processes, and various other accomplishments far outweigh someone who has done nothing but be a full-time student all of their life. Especially if it's not a top business school.
Before pouring time and money into more schooling it's best to determine what your overall goal is.
Look for people that hold the position you'd like to have some day. Do they all have MBAs? If so, then go for it.
On the other hand don't be surprised to learn that their (performance) in previous roles is what led to their station.
Some people need higher degrees to boost their own (self-confidence) before they'll go after their dreams.