In celebrating the exodus from Mitzrayim we need to eat poor bread, lechem Ony, made with only bread and water that is devoid of any flavor and not Matza Ashirah rich bread with any flavor. This is because through yitziyas Mitzrayim we came from being servants of Pharaoh to being avdei hashem, the servants of Hashem.
As servants of HaShem, we should not mix our own pleasure, into our avodas HaShem. Rather, we should accept HaShem’s yoke completely and make His pleasure our pleasure.
(הגדה עם לקוטי טעמים ומנהגים חלק א עמ’ קעה)
