The surprise is that it was decided by a 5-2 majority. Justice Patrick Crooks, who usually votes with the liberals, joined the four conservatives. Crooks gratuitously included an ad hominem lecture to the effect that collective bargaining is like chicken soup. But at least he was able to separate his proper judicial function from that reserved to the Legislature.
Via Act 10 and the Supremes: 4-3 it’s partisan; 5-2 it’s bipartisan consensus @ Blaska’s Bring It!