Well, I guess it’s up to the individual to decide if the campaign is worth the price tag. If the campaign is more expansive, high quality, takes longer to complete (15-20 hrs), and has more replay value than the other campaigns, then in my eyes that would absolutely fetch that price. Are games like Bioshock, the last of us 2, God of War not worth $60 in your opinion? The Halo Infinite campaign is a different experience, you are also welcome to wait to purchase it when the Co-op release which is the only campaign feature I’m aware of that is missing.
I hear your concerns about the f2p model for multiplayer, but I think the pros outweigh the cons. I’ve already seen the upside by being able to convince two close buddies of mine to give the multiplayer a try and now we have two new Halo fans. I can tell you having to convince them to pay $60 to try a multiplayer they weren’t sure they would like would have been impossible. Halo had been on a downward trend traffic-wise since reach so thinking that charging $60 for the full experience considering what the competition is doing would have been a grave error by 343. The f2p model ensures the game will keep a healthy population of players for a longer period of time. All they have to do now is listen to feedback, smooth out the monetization experience and we should have a Halo that can stick around for the long haul.