“Like a leaning wall, a tottering fence?” (62:4)
The concept of a fence around the Torah is meant to protect and honor the Torah by not letting get too close to a violation of its restrictions. An example — light Shabbat candles 18 minutes before sunset, so if you are a few minutes late, you have not kindled fire on the Sabbath.
A fence which is not well maintained or which is routinely breached does not honor the property which it surrounds. The solution is not to build a wider fence or higher wall, but rather to repair the current boundary marker and make sure people understand why it is there.