The "325,000" was referring to large amount of US code and possibly the poster was also thinking about the legal system being based around past court rulings. There are legal systems which do not place so much faith legal presidence. Such systems are much less foobar'ed due to activist judges.
The Supreme Court is BS. They do not decide truth or reality; within our flawed system they do have too much say-- but they are not the final word.... until a more corrupt Supreme Court makes up some BS to throw out an amendment and the citizens relinquish even more of their power to the bureaucracy, "the people" get the final word. They are old LAWYERS (they need not be lawyers...but we seem to think they must be.) Truth has nothing to do with the law; it's not science. If you want to pursue truth and reality you'd not put lawyers and politicians in charge of everything nearly all the time.
When you read the constitution and the amendments, it's clear that it was a well thought out legal document-- written before jargon made law an exclusive realm of professional lawyers.
When they use "the people" they are talking about everybody as a group, not individuals. The 1st amendment just before that one was worded stronger; they clearly could have phrased it with similar strength had that been their intent. Guns are clearly not on the same level of speech (besides they use "arms" which includes nukes.) It is really beside Jefferson's point which the poster was making: we are wasting too much time splitting hairs over some phrasing that is vague enough to be taken too many directions (that said, the Supreme Court interpretation of it is BS just like Citizens United or Separate but Equal.)
The poster; like Jefferson, is making the point that the document is not holy writ. It should be altered more rather than playing crazy word games with what is a fairly clear for such a SHORT document-- revisions would help clarify as long as they were terse and didn't blow up into craziness like the US Code has. The whole point of judges and juries was to INTERPRET and APPLY human intelligence to specific situations rather than try to program all possible scenarios on paper. Past arguments can be relevant but one shouldn't be wasting too much mental energy trying to morph them into different situations when people can just THINK out the new problem. (not like we don't have contradicting legal decisions despite our belief in legal presidence.) More thinking is required and less dependence upon paper "thought".
2 centuries is nothing. there are older democracies and many older governments. A good document will "stand the test of time" but time also... "time changes all things" so if the document is so good, it would heavily influence future revisions. If the system is broken then the new versions would reflect the corruption; keep in mind that corruption will not be stopped by some static document (it takes ACTIVE humans constantly fighting corruption - you can't stand still or let down your guard.)