This is true. But given the amount of government created dependency, entitlements, and a growing appreciation for Marxist concepts in this country, and knowing that a constitutional convention could also prompt a vote to rewrite most or all of the existing Constitution, that prospect raises all kinds of red flags in my head.
First, I agree in general that the chance of 38 states adopting a new constitution is zilch. The provision is in the constitution because quite a number of the Founding Fathers (especially Jefferson) did not believe than any document they came up with could last for more than twenty years. In the clause on the slave trade you can almost see them setting the date for the rewrite: 1808.
Lots of folks think that a rewrite could purge the constitution of a lot of dead wood; and God knows there is plenty there. Prohibition was adopted then repealed, scratch two amendments. We have multiple amendments amending amendments regarding the presidency and Congress (direct election of Senators, separating voting in the Electoral College to prevent ties between presidential and vice presidential candidates of the same party, moving date of inauguration up, electoral votes for the District of Columbia, presidential succession and disability, etc.) In the body of the constitution we could incorporate the bill of rights in the core document itself and cut out the specified powers of Congress which are archaic (how has Congress been doing on granting letters of marque and reprisal lately?). And how about the stuff for the Census, "Indians not taxed" and "3/5 of other people".
Anyway the biggest obstacle to such a rewrite is that it is not clear how 224 years of enacting legislation (remember the number of Supreme Court justices is set by the Judiciary Act, it is not in the constitution), and judicial construction of the Constitution (do we really want to start over in defining the commerce clause?) would be impacted. Our law rests on the virtue of certainty in many areas, people expect when they go to court that most decisions will be consistent with prior rulings. Does a Supreme Court case addressing an issue in the original constitution apply to a reworded clause in the rewritten constitution? If you think lawyers make too much money now, think what they could bill for these cases!