If you have no idea what to do with the data you've been given because you don't recognize what it is, then you do need those extensions. You are correct - if you don't need the tool, put it away - but the argument made in this article is that the decision was made that users don't need this tool and it is put away by default and the result is confusion...which is getting in the way of the work. The argument is that this tool is needed to eliminate the confusion which is getting in the way of your work.
I don't agree that users need to be educated regarding the significance of file extensions.
Yes, they do. Computers are not magic, they are tools. Tools a human uses to accomplish a task. The human needs to learn to use their tool properly.
Get over yourself.
Same to you, worker drone. You don't have a job out of the goodness of someone's heart. You have a job because it is cheaper to buy you than to buy the machine that can do your job. So quit your moaning about 'What?! I have to learn something? But I want to just push buttons like and ignorant chimp and get paid on Friday, why do I have to learn something?' and take some pride in yourself. Learn to do your job well.