Some Pharisees and scribes make the long trip all the way up from Jerusalem to Galilee just to accuse Jesus. News of Jesus' activities has apparently reached the top brass in the capital city, and they have sent representatives to get this loose-cannon rabbi in line. Their question, "Why do your disciples transgress the tradition of the elders?" shows that their main concern is about authority. "All religious practice done within these boundaries fall within our jurisdiction, you see. Why have you not asked our permission? By what authority do you do these things? Already we see how you teach your disciples to violate our traditions, which proves that you are a fraud."
Jesus comes right back and points out that the Pharisees commit the real offense by breaking God's commandment in order to keep their tradition. While it's unclear whether Jesus is condemning the practice of all man-made traditions, he is certainly aware of how traditions can end up usurping the place of God's commandments. They may start out in a subordinate place to God's law, then they move up to become equal to it, and soon they are taking priority over it. The tradition of Corban that the Pharisees practiced allowed them to take a vow dedicating their material wealth as a gift to the temple, which then made it unavailable for supporting their parents. Sorry, Mom and Dad, the money's been given to God. Conveniently, the sacredness of the vow took precedence over the fifth commandment.
Jesus summarizes God's view of such hypocrisy in this way: "This people honors me with their lips, but their heart is far away from me. But in vain do they worship me, teaching as doctrines the precepts of men." It's unsettling to think how many unspoken traditions we have layered on top of our Christian practice that may be taking us further and further away from God's actual commands. We have such definite ideas about how a godly Christian should dress, behave, talk, serve in church, evangelize his neighbors, prioritize his time, and vote. If any of these practices take priority over God's command to "love your neighbor," I think we'd hardly notice. Part of the reason for our blindness is that we can all think of ways that liberal Christians have abused and overused the term "love" to justify unbiblical practices. And yet that doesn't change the fact that God has still commanded that we love others, and has made that command supreme. Someone else's abuse of God's command doesn't give us reason to despise the command, nor does it justify finding man-made practices to put in its place.