Each one has their needs. I, personally, don't care for first person mode in pCoaster besides the "fake" one, that's enough for ME. Just being able to ride my attractions is totally enough. I don't feel like I need true first person to stand in line or go to an attraction's entrance to fix it being broken. So... you can ride your coasters and with the "cheat" you can walk in your park... that's really enough for pCoaster, which is not a game where you need to "care" -- not like when taking care of animals.
Now, even though pZoo is very similar to pCoaster, it does have completely different concepts, approaches, etc, because of being an animal management and care game. Their ideas for this to be an educational game to some extent and all REALLY calls for a first person staff mode. Sorry, but it definitely does. It'd be a waste If they don't add that to this game specifically, even if it doesn't come in the full release but later on.
Also, ZT1 is an isometric - and old - game, which makes it obvious why it didn't have anything close to a first person mode. That's not really an excuse, lol.