Simpler isn't always the thing to optimize for when people can't afford to heat their homes.
But you're right, we could also solve this problem very simply, without gradiated utility rates, by taxing the crap out of corporate profits and redistributing them to everyone else. This would punish corps who aren't building data centers, but if you don't mind turning the whole country into an AI server farm, I guess that would work too.
... Or, we could take the hit of extra complexity, and make high consumers pay extra, as I described.
Regulation and increased taxes/fees just make everything more obtuse and expensive, not better or simpler.