Can you explain what it would mean if it was voted for versus voted against?
Each day there is a budget for paying witnesses and workers. After witnesses get their cut, the remainder is available for workers. Workers will get paid in order of the total number of votes. You can add or subtract votes to a worker proportional to your BTS. The chain will then rank the workers and pay each worker one at a time until it runs out of money.
This 400k worker just returns the left over budget to the pool to be used the next day. Without this 400k worker, anyone could have made a worker and voted for it with 1 BTS and been able to pay themselevs whatever they want.
This worker is needed to provide the "floor" by which people have to have enough votes to overcome to become an elected worker.