Because electrification has become a panacea to policy-makers. A magic cure-all solution to all emission problems. So we decided that we will let electricity demand run amok, with no coordinated plan to keep power usage in check. In reality, ideas like reducing power demand and limiting electricity usage will be necessary, even if it direct contradicts previous policies. Ultimately, this is another heavy industry, and making it green is going to be extremely hard. Doubly-so, if you are planning to absolutely explode power consumption.
Sooner or later, something will give. Either we admit that we have to spend many trillions of dollars to upgrade the grid, or realize that electrification isn't the magic solution everyone thought it was. Heck, maybe even admit that some "green policies" were actually just corporate marketing from certain companies that benefit from electrification. You could even go as far as calling it greenwashing.