Steam Gamers settings for Predator are retarded.
Watch the same video you linked, the first 45 seconds...
Only 1 Zombie Spawns, gets teleported back, then gets grenaded 15 times by the same guy, to the point he can't move nor even know where he is.
If you are going to teleport zombies back to spawn, you need multiple zombies spawning.
Also, Predator supports zombie spawning in the middle of the crowd if you prefer it; there are two paths at the beggining, and that should quarantee plenty of Zombie Action; like the older maps.
Don't blame the map for not having zombies. Imagine Boatescape, Backmesa, Jurasick Park or any Old School Map with only 1 zombie spawning and getting teleported back... Seriously... ¬¬
EDIT: I'm sick of seeing wrong settings and people blaming it on the map. Not only here, but in many servers.
Not to talk about those servers were zombies are ridicously easy to kill, to the point they can't risk trying to go into a position that it's being hold.