Using separate wallets for gambling and savings is not only necessary but it is also a responsible practice. It is a form of self protection and personal risk management. If a person feels this separation is unnecessary, it could be a warning sign that they may not have adequate control or awareness of the financial risks they are facing.
Gambling of any kind, is inherently high-risk. Separating funds is one of the real ways to ensure that losses due to gambling never threaten your basic needs, future and overall financial well being.