Why the fees of coin withdrawal is different?

[mahbuboracle]

I know from the first crypto until now has not found the answer, why the fees of withdrawal is different?
Continue why else of all coins the cheapest withdrawal fees doge coin?

What can the market owner get if all the market users change their coins to the new coin doge make a withdrawal and what is the use of the withdrawal fee received by the market is the result of profit from a market itself.

If anyone can help me explain how this can happen ?