Yikes. Yes, of course technology is driven by human preferences. But, No, humans must occasionally accept that certain habits are not sustainable given current and near-future technologies.
I generally agree with your position but in this particular scenario the people with the greatest capacity to adjust their behavior are the people who will be affected the least financially by a hike in peak prices and thus less likely to change or more likely to invest in solar at home, while those with the least flexibility in work arrangements and spending, e.g. lower income earners working in the services sector, will be affected negatively the most and unable to work around it.
If the spot market was the status quo, and someone was suggesting a change to the current system of flat prices, one could make the same argument. (Ie already well off people are flexible enough to make use of the new system better.)
More variant pricing will better distribute usage. The unfortunate effects on the poor can be negated by a sales tax paid back to all citizens equally as a lump sum.