It isn't so simple.I couldn't agree less. If both 9 ball and 10 ball are played professionally, and as world championships, then the games need to be different. Otherwise why play both games?
If I recall, there is some history of "pool war" between 9b and 10b proponents. 9b was pool game of choice in international events until 10b came along to gatecrash the 9b party. Pros supposedly prefer 10ball couple decades ago so promoter/players push for world 10b championship. If I am not mistaken, that was one of reasons that Matchroom dropped out of promoting w9b when first WPA W10B event appeared. Also maybe why Matchroom used name "Pool" instead of 9b. Matchroom philosophy is single discipline-only 9 ball while other promoters believed in diversification/differentiation philosophy promoting multiple disciplines (9b, 10b, 8b etc).
W10B died off in early 2010s. Manny Pacquiao revived w10b for one year in 2015 until CSI revived it couple of years ago.
CSI/Predator started 10b tours US Pro Billiard/World Pro Billiards tours this year indirectly competing with Matchroom for slice of the peanuts pool audience market. Right now, they both can coexist since there are still not enough world class events so players can still play both 10b and 9b. Snooker world tour has around 20 events per year. Matchroom will keep increasing number of 9b events and Predator is aggressively adding tonnes of 10b events from this year. What if one of them reach 20 events soon? Then we may see both fighting for players or clauses added to prevent players from playing in another promoter's events. More events is good thing for fans and players though