First, have to have on mind that when we stop to do some sin or star to do some mitzva is just because is a G-d commandment. We cant understand the logic of G-d. Even if we find some logical argument to stop, probably is gonna be wrong and is gonna have another logical argument in the future to bet the first one because our logic is too limited.
So, my philosophy for why is a really bad thing for our humanity nature:
Imagine in a pure scientifically view:
If the human being cant masturbate. Is phisicaly impossible. (example ...made our arms to short to touch there...dont know...). Also
You have 16 years old, the age that starts the strong sexual desires. And until there you never had a sexual relation and, of course, you never masturbate, because you cant and because even don't exist this concept in our world.
One day, you see a lot of beautiful(tzanuot), sympathetic, intelligent women on the street, on your work, on your school. Then, you go home and... you cant do nothing about all the women that are in your mind.
The next day same thing.. Same the next...
One day, you gonna start to explode inside and feel the natural need of talk with some women. Why?? because naturally you need to release. And your mind will know that if you dont start to talk, you gonna keep feeling this forever...
If some kind of animal feel tired, it gonna sleep. Hungry, search some food. Thirst, search some water. A lot of libido, search a partner. If this kind of animal starts to ignore one of the natural desires. This specie will disappear after a while. This specie is gonna fail in the fight for survive.
So, scientifically, you are a specie of animal called human. And for your animal nature you shouldn't masturbate.
But we are not just animals.
G-d gave us the freedom to choice. You choose when you gonna sleep, what you gonna eat or drink, and with who you want to have sex. For what do you think is your best you gonna make all the choices. You can see that the best natural way of living for the human being is to be fat and spend all day in bed. But after a while, you gonna realize that this vision was immature and wasnt the best way to live.
We, am Israel, believe that we have a way to sleep, eat, drink, have sex, talk to other people, do business, etc...
Once, before the sin of Adam, all of this was natural for the human being. Now we have to choose things with our logic. And a lot of times we are wrong. Sometimes the scientists said that this kind of food is good for our body and mind, after a while they're saying that they we're wrong and this kind is bad.
So, because our logic is limited we have to follow whats the unlimited logic says.
One logical reason to not masturbate is to be the best human being.