I think you feel the situation is much more complicated than it is or that your take on it is somehow new. It's common knowledge that the largest media companies are owned by a few people. If you can't demand to have space on the pages of the New York Times or demand airtime on network television why can you demand to have space on Twitter?
It's funny to see that some of the people who are most alarmed by this truth, that we live in a capitalist society, are the same people who think socialism will be the death of us all. You're advocating communism when you advocate that the media should be owned equally by all people.
Certainly we live in a world where those who control what people read can have a great influence over what people think. This is a very old idea. As soon as language can be written it begins. It's been used for thousands of years. With the invention of the printing press it began to approach the levels we see today.
You are not owed a platform. And you're certainly not a free speech advocate.