Oh man.
This is about the 3rd or 4th post about invites this week, but from a sitter 
If you read these threads, you’ll understand why some HO’s think sending invites is how THS works.
No active sitters
Lack of calendar usability & education about the best way to secure a sitter is the route of the problem.
If you don’t want to receive any invites, you can either change your location to somewhere you want to sit, or you can write at the top of your profile something along the lines of ‘no sit invites please.’ (This usually works).