how else could you make sure a scarce resource (documentation of the truth in a decentralized manner) is distributed in a fair way to activities which get the most value out of it.
For example: if a bitcoin transaction would be free, a company like
https://www.bernstein.io/ would just sell this scarce resource for free and would therewith spam the blockchain with transaction where no bitcoin changes the owner.
Nobody said bitcoin transaction needs to be free but it's not really necessary to pay bitcoin as transaction fees. We are working on a second layer solution and we will be providing more information soon. It will change the way people look at transaction fees by giving power in consumers hand instead of miners.