I know you jest slightly, but I'm presuming the music company take an artist/band they think will make money and attempt to make them even more money whilst making themselves a bit on top. If you could do it all independentally then the bands would. Think of the equivalent of you filling in your tax return/paying an acccountant to do it for you.
However it has never been easier for musicians to go independent. It's cheaper than ever to get good recording technology. It's easier to distribute to masses through the internet. You can get your song on itunes. You can promote yourself in pubs/clubs. There have got to be far more people doing it now than there ever were, thus eroding some of what record label do.
However if you do go for the record label route, where you take half the hard work that you have to put in out of it (making the videos, setting up the recording studios, promoting the songs, albums, videos, tours, etc) then you can't complain when the record label tell you what they are going to do with them and tells you that you aren't going to make as much money as you would have before.
Plus you could probably replace the words 'musician' and 'record label' with the word 'journalist' and 'newspaper' in the paragraphs above then it wouldn't be any less true.