No one should even be using a wallet that has your keys and can actually send for you without password intervention. As that's proven to be very risky.
Let's let the market decide this.
An ewallet service that enables automatic subscription payments will be hugely valuable to everyone involved in Bitcoin. So long as they're trustworthy, there's no reason not to hold coins with them. Thus, it's just a matter of a company earning and keeping the trust and a mature Bitcoin market will have many such companies.
You trust the mechanic to bolt your wheels on to your car correctly, and the gas station to fill your car with the proper mixture of fuel. You trust the airline to not crash into the ocean, and the restaurant not to poison you. Trusting an ewallet will come in time