Its not that at all. Its just that we don't believe that your idea of democracy, will help us become more democratic.It's interesting that so many people laud the putative virtues of democracy but when true democracy is suggested they scurry back to the familiar comfort of rascals and charlatans to continue being fleeced.
There are serious concerns with your sortitionsuggestion, which should make any of us very weary of it.
*No Filter. You can't discriminant against idiots and dangerous lowlifes. There is a reason the majority of politicians are white lawyers.
*Radicals. Our system elects moderates, because it is a always a compromise of competing voters, your system will elect extremists. E.g. Right now there is no chance that a KKK or an Islamist could get elected, in your system, they could be.
*Loss of political culture. We would lose the need for political debates, primaries.
*Lack of legitimacy. If a president is there merely because of a ballot, why should we respect his/her wishes? At least with Obama, we know had the backing of the majority of us.
*Loss of enthusiasm. Politicians in our system only get the job because they have put in the effort to get there. They have proved their commitment to politics. Random people may have zero interest in politics, and will have little enthusiasm or desire for being a politician, and it will show in their performance.
*No accountability. Since you our representatives didn't get voted in, and they can't get voted out, why would they give a fuck what they did? At least Obama is worried about losing elections, this fear would not be there in your system.
If this system was as great as you make it out to be, you'd expect that there would be a few democracies using it today. The fact that our system is nearly universal with all democracies, is telling us something.