I still will never understand the need for Sony or Microsoft to want to franchise everything. Not everything is going to be Gears of War, Halo, Tomb Raider... Just let it be a stand alone experience and learn from it to create another game.
Franchises are viewed as infinite money printers. They think if they can get an intellectual property to "stick" long enough for two games related to it to achieve a modicum of success, they can just generate formulaic, derivative slop with Intellectual Property 3913™ Brand® elements inserted indefinitely and people will just vacuum it up as fast as they can churn it out.
Star Trek, Star Wars, Pokémon, Gears of War, Resident Evil, Silent Hill, Final Fantasy and stuff like that are all very successful franchises; even though they have controversial or unsuccessful individual entries in their respective series, overall those franchises have been very profitable to their owners. Of course, these examples are also showing their age and revealing the inevitable downside of a franchise -- eventually they become either over-saturated or out of touch with their audience, and people get tired of them and move on to something else naturally.
Star Trek and Star Wars have both had such dreadful entries in recent years they're effectively going on hiatus (Star Trek is all but officially mothballed for now, while Star Wars is still gurgling a bit but is also petering out). The recent Trek series were so out-of-touch with their audiences there's literal fan works that have more views than the official shows, and people are fucking sick to death of Star Wars shitting out the same cliched garbage every year too.
Pokémon, GoW, RE, SH and FF are all immensely popular video game franchises, but the latest Pokémon game has the lowest sales figures of any mainline game in the franchise, and the other franchises are all undergoing seemingly endless "remaster/reimagining" cycles instead of innovating new stuff.
The suits never see this part. They just assume any given entry in a franchise failing is the result of incompetence by the production team (which isn't always wrong, but also doesn't completely answer the question of why it bombed, and they never look too closely).
Besides, inventing new intellectual properties is hard work, requires genuine talent and creativity, and there's no guarantee even a genuinely good/compelling idea will translate well to the target medium and actually be a success (the public is a fickle beast). Much easier to shit a "new" idea out every ten years and shovel it into as many generic games as possible in the hopes of scoring a rare winner.