That's a bit dismissive. Goedel was correct about making the US a dictatorship. The fact that the amending clause allows unlimited amendment (particularly of the amending clause itself) means a series of malicious amendments could irrevocably change the constitution to that of a dictatorship and forbid returning to a democracy. Now maybe people would just give up on the constitution at that point, but in terms of the overall legal system he's dead right.
I've always thought it was more likely over article 2 section 3, which allows the President to adjourn both houses of Congress indefinitely under certain circumstances. If one was expecting to be impeached, for example, a little procedural hiccup on the timetable of adjournment would be sufficient to suspend legislative business altogether.
When we get to that level of a flaw, it is nice to remember that technically our own hollowed constitution is simply an illegal overwrite of the Articles of Confederation.
[edit: for more information please see: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2010183 ]