1) A rotating system of individual elections is far easier to manipulate since forces (coercion) can be concentrated on one election at a time, where under simultaneous voting, it is extremely difficult to coerce every race without nearly infinite funds.
2) With the advent of communication there is no reason for representatives any longer, whatsoever, nor for the houses of congress. There is every reason for either devolution of all power to the states, or direct democracy (equidistribution) or direct proportional democracy (by contribution). [There isn’t any reason for one single currency for all purposes any longer either. Nor is there any reason for distribution of liquidity through the financial sector and the credit system. In fact, that’s the source of the economic problem we face today.]
3) Because it it is far too easy to influence politicians whether they are elected incrementally, through rotation en mass (as now), or all at once (in the athenian method).
4) The purpose of scale whether at the jury, state representative, or federal representative level, is to increase the cost of bribery.
Ergo it is time, given our wealth, to increase scale from representatives to the entire populace, since that bribery is impossible for OTHER than the state.
(As for ‘comparison of legislatures to juries, the evolution of the legislature being Thang 12, 20, 100, or more, depending on the severity of the matter) > The Jury > Senate > Multiple Houses > Direct Democracy, is … well you’d have to be relatively ignorant of the origin of the western tradition and its roots in the sovereignty of individual men, leaving the Thang (Jury) as the ONLY POSSIBLE means of choice, and the Headman, Chieftain, King, Monarch, as a Judge of Last Resort.)