my former parish has the Blessed Sacrament exposed for Adoration 8 hours every day, and the new pastor shortened the hours because there were several times the chapel had been left empty and unlocked because someone did not show up, had to leave early for whatever reason. Also some people had the mentality “I own the hour from 2-3, nobody else is allowed in here during MY time”. The secretary was continually be called out of the office to repose the Blessed Sacrament or to take the hour herself, or calling people to find substitutes. Also the Church is downtown, and street people frequently come in the chapel, and were frightening or even harassing elderly people who were there alone.
To correct abuses he now allows shorter hours and has new regulations. 4 people must sign up and commit to each hour, and must find their own substitutes, to insure that no one is there alone, for safety, and so that these problems do not occur again. Not a Church rule, the pastors rule, for wisdom and prudence.