It is only your opinion that "the excuses Christians make for this passage are pretty worthless". You are clearly trying to find flaws in Jesus' teaching (specifically) and Christianity (in general).
Why should anyone accept your opinion about the Sabbath and ignore Jesus' teaching?
Mark 2:23-27 [with my comments inserted and my emphasis], "One Sabbath Jesus was going through the grainfields, and as his disciples walked along, they began to pick some heads of grain. The Pharisees [legalistic Jews] said to him, “Look, why are they doing what is unlawful on the Sabbath?”
He answered, “Have you never read [in the Jewish Bible] what David did when he and his companions were hungry and in need? In the days of Abiathar the high priest, he entered the house of God and ate the consecrated bread, which is lawful only for priests to eat. And he also gave some to his companions.”
Then he said to them, “The Sabbath was made for man, not man for the Sabbath. So the Son of Man is Lord even of the Sabbath.”
Ergo, your biased explanation is worthless.