If you're paying for the electricity fairly, why should someone have a say in how you are using it? Electricity companies could limit these people, but they choose not to.
I agree with your point in principle but there are numerous examples where this kind of approach reaches major roadblocks. If you have limited energy generating capacity and that energy is depended upon for life essentials (e.g. heat, light) then there comes a point that ramping up energy price due to people being able to make a profit off the back of it means cutting off other people's access to life essentials because they are priced out.
We see this elsewhere as well - For example, production of biofuel occupies productive farmland. If farmers can make more producing biofuel crops than food staples, they'll chase the money. This leads to a rise in food prices and pits the price and food against the price of fuel.
