Everyone can get frustrated at noise or lights. People with autism are especially sensitive to it. Your mind has the ability to filter out an extraneous sound or a slight flicker to a light. However, a person with autism may not. It may be a trigger for them and it may not be obvious to neurotypical person.
People with autism may not have a mind that can filter out what is important. They put as much attention to the electric fan going as the sound of your voice. The chair is as important as your face. They take in sensory input and cannot prioritize.
That is why they cannot identify social cues. Everything is coming at them. So you can see why a child with autism may have a tantrum or act out to avoid something. They are as tired as we might be if we attended a long boring conference all day.

They then might need some time to recharge. Avoiding social contact may not be anti-social. Kids with autism are often video gamers. They can forget about everything else and focus on what they can control.