The Alternative Vote was defeated because almost nobody really liked this voting system. The LibDems preferred the Single Transferable Vote, and other campaigners preferred proper proportional representation.
The Alternative Vote (AV) had been chosen as some sort of compromise during the Conservative-LibDem coalition negotiations, but the Tories campaigned against it regardless, and the LibDems were then forced to try and persuade the electorate to support a voting system they didn't really like themselves.
So it's likely many people voted No because they weren't convinced by the merits of AV, not because they were against a reform per se.
However, the No victory buried all hope of another voting system for a generation, because it was interpreted as support for FPTP.
If the Yes side had won, it would have been possible to change AV into something better a few years later, but the No vote was effectively a vote for the status quo.
The lesson for the Scottish independence campaign is obvious.
Many No campaigners argue that all sorts of wonderful reforms will happen after a No vote, but in reality it's very likely it will be interpreted as a vote to keep things as they are.
A Yes vote, on the other hand, will make it possible to discuss many other reforms in Scotland -- such as abolishing the monarchy -- that just aren't on the agenda at the moment.
I actually feel sorry for the Devo-Max supporters out there. It's a very popular vision for the future of Scotland, but by keeping it off the ballot paper the Westminster government has ensured that it will never happen. We'll either get full independence or nothing at all.
All Devo-Max supporters must therefore face up to the reality that their preferred option won't suddenly be resurrected after a No vote. They have to decide whether their favourite outcome is closer to the current devolution settlement or to independence.