I have to agree with @BuckeyeNut on this one; when players go out in the morning, they often take the option to play again if it becomes available. Slow play doubly screws those players because it packs the course for the second 18 in addition to spoiling their first. And of course, they pay the most money so it becomes a really poor value for them.
As far as level of play, I don't really judge. If you can keep a decent pace and you want to pay the extra money I don't begrudge you. Most players I meet aren't low handicaps but most know how to navigate the course and be considerate to others. When someone is an outsider we know it based on their pace of play.
I prefer to play in the afternoon because it's always easy to find open holes as a single or pair no matter where the players are. I sometimes have to play guerrilla golf but pay a lot less for the privilege.