folly is set in many high places, and the rich sit in a low place.
The scope of these verses is to keep subjects loyal and dutiful to the government. In Solomon's reign the people were very rich, and lived in prosperity, which perhaps made them proud and petulant, and when the taxes were high, though they had enough to pay them with, it is probable that many conducted themselves insolently towards the government and threatened to rebel.
Commenting on Ecclesiastes 10:4-11
Folly is set in great dignity,.... Or "in great heights" (q); in high places of honour and truest; even foolish and wicked men; men of poor extraction, of low life, and of mean abilities and capacities; and, which is worse, men vile and vicious, as Doeg the Edomite, Haman the Amalekite, and others; and the rich sit in low places; men not only of fortune...
rich--not in mere wealth, but in wisdom, as the antithesis to "folly" (for "foolish men") shows. So Hebrew, rich, equivalent to "liberal," in a good sense (Isa 32:5). Mordecai and Haman (Est 3:1-2; Est 6:6-11).