Smart playlists are in the songs database, and not in the playlist file.
The first thing I see about your term is the word “OR” … so if the genre would be Holiday, it isn’t Podcasts, and if it is Podcasts, it isn’t Holiday… all songs would fit.
You already wrote the proper term, just not in uppercase: “AND”
genre not = "Holiday" AND genre not = "Podcasts"
To tell it to ignore both.
By the way, what exactly does “not working” mean (that’s kind of an error description everyone just loves 😉 ):
* Does the playlist not show up in iTunes at all?
* Does the playlist include all items on the list (which I would expect from your term)?
* Does the playlist include no items at all?
etc.