You tell lots of random people you are going to do something that doesn't make any difference to the outcome. You do that and then tell random people that you did that something that doesn't make a difference.
Random people laugh.
You say that random people are spiteful to laugh. If you think what you said, then did, you might in time laugh too. You may not get why people find it amusing. Fair enough.
Personally, I'm glad lots of people can be bothered to speak up and vote, whether their choice wins or loses, they did their bit to help the country select the next government. As another poster said we don't get the opportunity very often.