Not sure I agree with you. Sick to death of all the old humvees, M4 variants and AKs. I'm glad they took a change in direction and went for something fresh. Although there is currently no where near enough unique content for an Arma game.
I understand some like the way its gone, that’s great.
But we never had the boredom thing that many talk about with Arma 2, Arrowhead, CO etc. You know, same weapons, setting and factions.
Our group uses multiple factions, around 20 I guess at last count, probably a few more thinking about it. There are 45-50 supported terrains (for the AI conversion mod we use), plus assets/equipment/weapons etc, they must run into hundreds (many hundreds probably). So the way the game is setup has a world feel, i.e. different terrain types, from snow to desert and most things in-between. Huge selection of weapons, vehicles, equipment and so on.
So that kind of thinking, we didn’t have anyway. It was the opposite we had.
However, we looked at Arma 3 and was quite excited about it until it arrived in early Alpha and we’d played it a while. But as said, with all we had going on in Arma 2CO, we more or less went straight back to it.
We knew we couldn't loose all the things we'd have to leave behind.
The biggest factor for us anyway, was that KAI is only for Arma 2CO, they withdrew the Arma 3 version because of the problems BIS were having with the standard AI. Guess it was hard to work on AI that was also being worked on by the devs. Whereas in Arma 2CO its finished, so the mod stands well without much support, although there is always ongoing updates of features within the mod.
KAI is a full conversion mod, it changes the game completely really, so it would be hard to go over to Arma 3 anyway.
Still, with all that said, its a case of, you have to mod the series and mod it really well, to get a really great military war gaming world. Its all personal preference at the end of the day, isn't it.