(Before anyone brings up the Tesla battery in Australia, that is an edge case where the grid needed more capacity for grid stabilisation. Almost anywhere where you would find one of the electric pickups from the article would also have a stable enough grid that you cannot replicate that with the car battery.)
3000 cycles is already 10 years at just under 1 cycle per day. Adding an order of magnitude more cycles by cycling between 75% and 25% gets you a century. Something else is going to die first.
5kwh for $1500 with 3000 cycles is $.10/kwh. I'm oversimplifying here as the real cost is higher, but the arbitrage opportunity only has to offer ~$.20/kwh to be generally profitable with a battery like that.
Some time of use plans are already there daily. I don't think the person taking advantage of this sounds like any "kind of idiot".
FWIW, Ford has sold out of these for the next 2 years, so they must be doing something right.
But honestly I don't know, it's not something I've looked into. If prices become increasingly variable coupled to demand and impact of generation source at time of use, I imagine it could be quite lucrative and that might be a useful incentive to get effectively decentralized peaker plants in the form of grid-tied residential batteries caching cheap cleanly-sourced electricity.
$32 / MWh wholesale is an arbitrage that could be done on many days in CAISO today. I don't particularly think that people will use that much of their battery or do so every day of course but it does show that it's not an orders of magnitude implausible scenario either.
So I can do the electricity math for myself, but not for others.
The kind of idiot that wants to generate income through arbitrage by storing energy in his EV when prices are low and selling it back to the grid during peak hours when prices are high?
Don't forget the kind of person buying this kind of vehicle today also probably has a multiple car garage.