Note that millet and polished rice are at opposite ends of the supposed quality spectrum, for completely different reasons…generally, serfs ate millet, while lords ate polished rice. Chinese sources identify this glyph as white rice, and not as millet.
「Depraved rice」is POLISHED RICE with all the nutritious hull removed leaving only the starchy, high-caloric carbohydrate center for causing heart disease, diabetes, and obesity…or the elements are「rice grains for those who are despised and depraved, greedy, gluttonous, avaricious, contemptible, disdained, scornful」meaning the wealthy upper-class aristocrats.
Other sources assume「rice grains vulgar」were the poor man's grain as pearl MILLET, and「rice despised」if indeed this glyph does refer to 'barnyard millet':「Echinochloa crus-galli is a type of wild grass originating from tropical Asia that was formerly classified as a type of panicum grass. It is commonly known as cockspur (or cockspur grass), barnyard millet, Japanese millet, water grass, common barnyard grass, or simply 'barnyard grass.'…. The seed heads are a distinctive feature, often purplish, with large millet-like seeds in crowded spikelets. Considered one of the world's worst weeds, it reduces crop yields and causes forage crops to fail by removing up to 80% of the available soil nitrogen. The high levels of nitrates it accumulates can poison livestock. It acts as a host for several mosaic virus diseases. Heavy infestations can interfere with mechanical harvesting. Individual plants can produce up to 40,000 seeds per year. Water, birds, insects, machinery, and animal feet disperse it, but contaminated seed is probably the most common dispersal method.」
[ https://en.wikipedia.org/wiki/Echinochloa_crus-galli 2013-10-20 ]
Furthermore, MILLET is a Chinese euphemism for encrusted gonorrhea gleet on the tip of a woody stalk, hence: COCKSPUR, and contaminated seed is probably the most common dispersal method for the bacteria, also.

External source definitions …excluding politically incorrect concepts and other meanings deemed offensive today; may include extended definitions, euphemisms, and mnemonics)
Chinese: polished rice; old variant of 稗
Japanese EDRDG: polished rice or millet
Unihan extended: polished rice or millet