Slowly.
There are a limited amount of strong, really good shooters in any area, as well as at the national level. If there are many divisions, that means that the number of the strong competitors in any single divisions is declining. For example, instead, say, 10 M and GM in Production, there would be 5 in Production and 5 in CO. Then 3 in Production, 5 in CO and 2 in PCC. Everybody is a winner, LOL.
To me the main reason to shoot USPSA is the competition. The adrenaline rush is addictive. If I find myself in the division with 3 shooters, I will have to find a different division