None of the above.
It is about the way contracts for difference work in the electricity supply market. Where the market cost for a unit of electricity falls below the agreed strike price, the government i.e. us the tax payers step in to make up the difference.(For the solar / wind supplier, heads I win tails, tails you the punter, lose!).
Octopus the retailer are far from mad, but spotted a business opportunity to purchase units at significantly below market cost and bung it to the punters at a discount and still make a profit (no doubt encouraged by arm twisting from HMG who are getting increasingly embarrassed at the ballooning cost of paying the wind and solar providers vast quantities of your cash for not supplying energy )
If you want to call out the madmen, look to the UK Treasury and the great and the good therein that set up the whole ludicrous mess in the first place.
You will get the opposite effect when demand is high and needs to be offloaded, i.e. you will be paid to switch off your washing machine etc.
The idea is for variable charging via smart meters, but for it to work everybody has to have one and assumes that nobody will get pissed off by not knowing what their electricity will cost at any time of the day.
Symptomatic of a failing energy supply market I”m afraid.