The first thing- About music

I've wondered. Why is it that vocalists are better appreciated than instrumentalists. When there are many who listen to the melody part of music and like it, its not like the words are too important. I'm listening to Somewhere I belong by Linkin Park. So when you sing it, the music is not impressive, which shows that instruments are definitely needed in Western Music. But still the singer gets to occupy the central position on stage. So is there something special about our voices? Instruments are made by us after all, they are just imitations of what our voice can do. Besides its easier to sing than to play any instument for most. So its like appreciating the person who invented the chair more than the person who invented the computer. Anyone can invent the chair, like how anyone (or most) can sing. If we didn't have chairs, we would've sat on small boulders first, then moved on to something lighter and portable, inventually we would've made use of wood or something similar to create a chair. But Charles Babbage thought of something revolutionary. So. Why are vocalists better appreciated than instrumentalists?