The EU has been pulling this stuff for a while. Back when Ireland had a referendum whether they should ratify the Lisbon treaty the Irish voted against it. A year later they were asked to have another referendum with some concessions given by the EU.

Referendums don't really work if one side can just ask to have another one.

I would say it's standard in most western countries.

Eastern countries too, unless they're too totalitarian to hold votes.

That is probably a property of representative democracy.

It's a property of all systems. Some asshole is going to try to abuse it to enrich themselves. That's why checks on power are so important.