Direct democracy requires substantial amounts of investment in public education. Not every citizen would be starting from the same knowledge base or have a similar desire to take on responsibility for the complex affairs of the state. In a modern state, with competing demands for public spending there is no guarantee that taxpayers would want to meet this heavy cost or that individuals would be willing to pay this personal price.
In a direct democracy the affairs of the state are the responsibility of every citizen. They cannot leave them to elected representatives or economic elites. This ensures that every citizen has the incentive to participate and it encourages the state to make sure that every voter has a high level of education of public policy so they can properly dispense their duty. A consequence of this is that it ensures that citizens have a higher level of ownership of the policy decisions made compared to their counterparts in other states, and a civic responsibility to their fellow countrymen with whom under this system they are forced to cooperate.
[P1] Direct democracy requires huge amounts of resources to educate people. [P2] This is not a good use of resources.
Rejecting the premises
[Rejecting P2] This use of resources is worth it to have an engaged electorate.