The Constitution was SILENT on women's suffrage until the 19th Amendment was ratified. That silence meant that the issue of women's suffrage was left to the states. States were free to give women the vote, or not to give them the vote. They could also enshrine either of those positions in a state constitution, if they chose to do so.
That is the worst explanation I have ever seen. The heart of the Constitution is freedom, life, liberty for all. Free speech for all, including voting because it is an expression of freedom of speech.