Any law or ruling passed in the parliament having a clause that state Govt could apply it in their states or not is a dubious one and gives freedom to the state Govt for implementing it or simply ignoring it. So, this is a fallacy in the system and sometimes in state level some adamant and influential people are at the helm of affairs who will ignore the directive made by centre. If we recall and remember that during GST debate it took a long time in getting the states agreed to the new tax regime and main reason was the state quota in it. States want revenue and GST was a lucrative one so once it was decided that 50% of GST will go to the states then only after a lot of deliberations they agreed for its nationwide implementation. During demonetisation, there was no option given to states to continue with old currency (which would had been a ridiculous thing), if they wished so. As there was no option, old currency was completely removed from the country. So, rules and regulations are generally followed as per the options therein. But sometimes some adamant state level politicians oppose the normal rules also and create problem for the centre Govt. It is the way some people use politics as a tool to show their power and authority.
Knowledge is power.