A dog's life within Direct Democracy

As many of you may know some 24 U.S. states utilize Direct Democracy to force their legislatures to listen to their citizens' demands. In the November 2010 House of Representative and Senate elections (the one that reduced the Democratic Party control of the House) several states also had votes about local issues on the ballot. Indeed some 155 local issues were so determined. One of the more interesting ones was in Missouri. Odd as it may seem, within Missouri there are almost 1500 licensed commercial dog breeders - which between them breed about 1 million puppies per year. There may be even more that are unlicensed. Animal rights lovers had been trying for years to get better standards passed to overcome some horrific conditions there amidst some puppy mills. And so they gathered some 190,000 signatures in support of what was called - The Puppy Mill Cruelty Prevention Act. And this was approved by the majority of Missouri voters. The new amendments in the law will provide clearer, enforceable standards with sufficient fines for breaches of them. Indeed, it is hoped that other states will follow Missouri in enacting better standards there, now, as well.
This is a rather remarkable effort via citizen-led Direct Democracy to change laws which their elected representatives did not have the gumption or desire to do.
Why cannot such Direct Democracy initiatives become part of the law in other supposed democratic jurisdictions - such as Ontario?
All of this was reported in the Nov. 13 issue of the Economist magazine.