I think this really makes sense given that in Germany we have a quorum of 50k with a much smaller population. The same thing is probably true for other smaller countries as well.
(By contrast, the U.S. has 30X the land area of Germany.)
However, on the state level there is a "Volksentscheid" where the people can directly vote or enforce a vote on an issue. The quorum and the topics that are eligible for a Volksentscheid depend on the states legislation. Berlin for example allows a vote on general topics of interest while other states only allow votes on proposed laws.
[1] you know, against child porn. See http://en.wikipedia.org/wiki/Zugangserschwerungsgesetz for a short summary.