Because bad people can't be correct, and anybody that thinks differently than me and has made a mistake in their life is a bad person. Actually, even if they have never seen them make a mistake, they are still bad, because someone once said they were horrible people.
I don't argue with people, I have never seen an argument ever actually solving a mutual problem or changing someone's opinion.
I'll have to argue against that, arguments change people's minds all the time.
Let's take a basic example to illustrate. You are living with your significant other and want to do some random activity one weekend. You go tell them your plan, upon which they argue that you shouldn't do that because that would conflict with a prior arrangement you had. You look at your calendar, realize they are right, and are convinced.
This is a relatively simple example that can show how easy it is for arguments to change people's opinion everyday. I think arguments are very important, as they are the basis on which we can discuss and compare our different viewpoints.
For a broader example, let us think of our technological advancements. When Newton first discovered gravity, if he had just said "the earth is pulling us down", do you think that would have convinced everyone? No, and that is why he had to argue and show proof, after which his theory of gravity was widely accepted. Teh same goes for any scientific theory, it needs to be heavily discussed, weighing the arguments for and against, before settling on the most reasonable theory. If scientists did not argue every day, then our science would have been limited to single viewpoints forever, and we would never have progressed thus far.
No of course this becomes very complicated if the issue is very large and vague, or if there is a heavy emotional attachment (ie politics), and it is easy to devolve into simply repeating your point of view without evidence, but that is no longer an argument. The foundation of what makes an argument valuable is still there, and you can't dismiss it.
Of course, if you personally find that arguing against someone is not worth your time that is fine, but saying that arguments do not convince people is not true.