The laws of the meal offerings required that they be salted, but there could be no leavened dough or honey (Leviticus 2:11-13).
Temple offerings were supposed to both impact us spiritually and reflect our own spiritual growth. Leaven causes dough to rise, to puff it up. Honey, as well, artificially enhances taste. In both cases, the real qualities of a food are masked.
Salt, on the other hand, brings out the actual flavor of a food. It allows it to be fully experienced and appreciated rather than artificially made over.
The goal of the Torah, including the Temple practices, is to serve as a catalyst for real growth as an expression of our true innermost selves. Superficial makeovers are not the order of the day.