Well there are cases where a habit of daily or weekly masturbation over a period of decades can cause a decrease in libido and staying time.
When you're used to doing it quickly for 20 years before you meet the right woman to marry, you might not last long enough to satisfy her.
That is why it is encouraged to use masturbation to see how long you can last before blowing your load, and not always going for a 'quickie.'
Also, some men can't keep it up because it doesn't feel like their hand. A woman's vagina can't be as instantly adaptable in size, pressure, etc. as your hand.
In some of those cases, a twisty type of condom can be used to help guys in those situations to help them have the feel of their hand, while having sex.
The main point is - don't marry your hand, unless you'll know that you'll live happily ever after.