There was some reference on the FB JMT group attributing the change to some scene in Bishop: "few abusers have ruined it for the rest of us". I assume this means dirtbag hikers and homeless hanging around Bishop.
I've got news for Inyo NF and folks in Bishop: people like that are hanging around more and more everywhere. Punishing hikers is not going to change the problem one bit.
If there are hikers who are actually using one permit to hike all over, it would be pretty easy for rangers checking permits to write on the back the date and location checked. Then if they showed up in some not-continuous or way-off date, it would be easy to determine they are abusers.