Austria’s interior minister Gerhard Karner recently stated that the government he is part of still believes that the Schengen area is “not functioning,” which is why they do not agree to expand it with the addition of Romania and Bulgaria. During a meeting with the Romanian interior...
Pretty sure that this is Austria doing it and for domestic political reasons.
And while I agree that attempts by countries to leverage their “inside before others” position to block other members is obnoxious, there have been vetoes from any number of countries. A while back, Greece was threatening to veto things to shift positions on Cyprus, for example.