Also our electricity rates fluctuate based on the underlying wholesale rate. It's going to be clear and sunny tomorrow at midday. Sure would be nice to be able to set my car to charge at midday when the price is single digits cents per kw, or maybe even negative. Instead I'll just have to drip it in with the higher rates at midnight-6am and know tomorrows cheap rates will average out to a much lower cost.
TLDR: definitely useful even for people who charge at home.