All the motivation is for merchants. They avoid merchant fees. They get no chargebacks. But they're also going to get no sales (aside from enthusiasts), because consumers have no incentive to use it, whatsoever.
Where are the perks for consumers, in a situation where they're buying something with bitcoin?
I think the idea is that merchants can give a discount for using bitcoin just like some do for cash. I know that Amagi Metals gives people who pay with bitcoin their "cash" price while people who pay with credit cards pay a higher rate. So the trick is how merchants encourage customers to use, if they do I think many will.
But otherwise you, and many other posters, are correct, there is no intrinsic advantage of bitcoin over other payment systems for consumers.