The simple answer is just to make life easier. We invented tv remote control, so we didn't have to get out of the chair to change the channel. Some people own complex media systems, that require the owner to press 10 different buttons on 5 remotes, just to watch a movie.
Home automation system eliminates the need to walk from room to room to adjust drapes,lights ,temperature, and your audio/video components. Total control is always at your fingertips.
Your Home is a place where you and your family get together after spending their whole day out.so it must be haven on earth..
With the help of Home automation you can control all the appliances of your with your smat phone from any part of the word. You can schedule devices to turn ON and OFF at a specific time, create perfect ambience mood lighting, monitor energy consumption and can save lots of electricity bill.
Now you can control your devices with your voice commands. Its like alibaba's SimSim tales.