The placement of a thermostat in a house should reflect the greatest needs in the house for heating or cooling, in the place where the temperature needs most to be controlled or at a central site at which the needs of the house can all be assessed. The placement of the homeostatic centers in the human brain then makes sense because the brain is the most critical part of the body for temperature control, and it is the place to which information about homeostatic needs throughout the body comes.
Work Step by Step
Try to imagine parallels between the house and the body-- where is control placed, why there in terms of needs and in terms of the information required for successful and healthy homeostasis. These parallels are the basis for the answer to the question.