The Raaviah holds that we don't have to recline anymore today because that is not an expression of freedom. Today freedom means sitting upright. But he is a singular opinion not accepted by other authorities.
The Rambam writes:
"לפיכך כשסועד אדם בלילה הזה צריך לאכול ולשתות והוא מיסב דרך חירות."
Reclining is an expression of freedom. The fact that we have lost this feeling does not detract from the reality. Therefore, we must recline.
Rav Meir Chodosh adds that an eved says "אהבתי את אדוני את אשתי ואת בני לא אצא חפשי" - This eved LOVES his Master and new family. He wants to remain an eved. We want to educate him that the only master one should have is Hashem. That is the idea of boring a hole through his ear, showing him that he didn't "get it" when he was told that he is exclusively an eved Hashem.
People today think freedom is doing whatever they feel like whenever they feel like it. We have to educate ourselves and others that true freedom is being in control of ones passions and desires.
