I don't think this is a demand at all... It's actually opposite from a demand. A demand is me telling the guy if he doesn't marry me or propose to me, I will break up with him. Me saying I don't mind proposing myself is simply me stating I don't adhere to old-fashioned stereotypes and I won't allow anyone to control my fate.
If I propose and the guy loves me and want to spent his life with me, he's accept. If he doesn't love me and he doesn't see me in his life, he'll reject and I won't be wasting my time. Granted, both parties have to believe in marriage and be together for a while.