I really like to play with beginners........Is there anything i can do to stay in White Belt

No, there is nothing you progress and have to fight better players.

Beginners don't want pro's destroying them all the time, that's what forces the new guys to quit already.

Try playing 25,000 games then you can be whatever belt you want.

That's why they make servers full of people with/around your same belt and skill level, that's always where i played until those servers weren't there anymore because i had a higher belt.

The point of the game is to progress. Not bitch and whine because you're getting your ass kicked in the blue belt servers.
But if you want to constantly create alts to stay white belt, by all means. Do it. I'm not sure there's a specific rule against it.

It would be cool to have an everstone item object.
"Mash B to prevent belt graduation!"

But yea, these people here answered it pretty much. It keeps you in the right skill level ingame. Sure, you can keep creating alts over and over again to keep fighting white belts but where's the satisfaction in that? Eventually you'll just want to progress and when you do you won't even have improved since you were fighting white belts the whole time.