The CEO goal isn't to create new IPs or to create large portfolio of games though. It's to increase the value of the company and help ensure it's future. Having a lot of games that sell okay isn't really desirable. Each new project introduces risk and the reward has to be worth it that they put up tens of millions of dollars up front to make it. The reward has to outweigh risk. It's why a lot of companies will spin-off/sell-off divisions that are profitable. They rather just make a profit on the sale and focus on more rewarding businesses than to allocate their finite funds into high risk low reward projects(investments). Activision seem more interested in capitalizing on trends with promising prospects than to find market "gaps" or to offer a big range of games. For example, there's RTS genre that isn't getting a lot of games made for it. It's not a very promising market and people aren't making a lot of those games. There's still money to be made if you can be good at it. But adding a few million to your bottom line after putting in the same amount of time/money/effort isn't as worthwhile as potentially adding hundreds of millions or even a billion to your bottom line by putting the money elsewhere. For someone who just loves making games or doesn't have a lot of money that's great. But for a big multi billion dollar company trying to double, triple in size, it's not worth the effort/money/risk.
Activision never really had that many franchises. They have a long history of just making licensed games. Sony creates new IPs but they also abandon IPs too. Nintendo doesn't really create new IPs and they don't really focus on all of them. There hasn't really been an Fzero game for a while, and I don't think you'll see another kid icarus game for a while. Sometimes your IPs aren't worth investing in anymore. Neither of them really just fill in gaps. If anything it seems like Microsoft does that a lot more considering they are creating such a wide range of games nowadays that aren't necessarily very popular genres. Sony gutting Japan Studio is probably an example of them being closer to Activision nowadays as the reasoning was that they weren't profitable enough.
With all that said, I do think they should take more risks though. They don't need to have a big list of games or fill in the gaps. But they should still try to find the next big thing. Either way what they are doing, seem to be working.