That's a lie. They didn't find the later manglings of the Miller decision pursuasive. Ones which claimed the Miller decision said things that literate people could not find in it.
Cases v. U.S., 131 F.2d 916 (1st Cir. 1942), cert. denied, 319 U.S. 770 (1943)
...if the rule of the Miller case is general and complete, the result would follow that, under present day conditions, the federal government would be empowered only to regulate the possession or use of weapons such as a flintlock musket or a matchlock harquebus. But to hold that the Second Amendment limits the federal government to regulations concerning only weapons which can be classed as antiques or curiosities,--almost any other might bear some reasonable relationship to the preservation or efficiency of a well regulated militia unit of the present day,--is in effect to hold that the limitation of the Second Amendment is absolute. Another objection to the rule of the Miller case as a full and general statement is that according to it Congress would be prevented by the Second Amendment from regulating the possession or use by private persons not present or prospective members of any military unit, of distinctly military arms, such as machine guns, trench mortars, anti-tank or anti-aircraft guns, even though under the circumstances surrounding such possession or use it would be inconceivable that a private person could have any legitimate reason for having such a weapon. It seems to us unlikely that the framers of the Amendment intended any such result.
It seems quite likely to me that the framers intended exactly that result - and that they were quite explicit about it.
But we've had 60 years of lower-court decisions, referencing "Cases", and pretending that it somehow discovered a "collective rights" meaning in "Miller", when "Cases" in fact, did exactly the opposite - it found a strong "individual rights" meaning in Miller, and then intentionally ignored it.