Grandparent might be referring to the fact that the founders' vision of limited government was of a government much smaller than what we have today with much less interference in people's lives. If they were alive today the founders would likely be shocked at just how much the (federal) government does and how much it impacts daily life. Since the government was expected to do much less than it does today, voting would have a much less significant impact on people.
Concrete examples that did not exist at founding include:
- social programs (welfare, social security, unemployment benefits)
- high levels of military spending/military industrial complex
- income tax
- many of the executive branch regulatory and other agencies
George Washington's cabinet had only five members: himself, the secretary of state, the secretary of the treasury, the secretary of war (now defense), and the attorney general. Nothing else - no Department of the Interior, no Health and Human Services, no Department of Education, no Department of Energy, no Small Business Administration (just to name some that come to mind).