mom of a 'beginner' 65 rider here, so go easy on me....i think i am the 'mini parent' that brought up splitting the 65s when the class list was released for the OMA. we had just bought our first 65 and the thought of braden on the line with possible 12 yr olds made me cringe! even though the joke was on me, since the beginner class was 65/85 riders that could possibly twice his age.
main reason, confidence. we all know that a little 'i can do this' goes a long way in this sport. look at the kids body language as they walk away from the results postings. 7 yr old, rode his ass off, goes to look at results and sees his name on the bottom half of the list, lowers shoulders, and walks away thinking what the crap are the chances of me ever getting to the top of that list anytime soon. whereas, if they were split, 7 yr old sees his name in the top half of the list, does a silent (or verbal) Hell Yeah!, runs back to trailer and asks when the next race is!
i will be the first to admit that we are working very hard on the 'doesn't matter how much older they are, you are in the same class, so go get it' mind frame with braden. he has a crappy december birthday and we created this 'but they are older than me monster' and have been working to not even bring age up. BUT, like james said, the physical and mental difference between a 7 yr old and 12 year old is HUGE! braden can't even touch the ground on his 65 so, if he goes down, there is a chance he may need help(maybe not so much now, but at the beginning of the season for sure). at the beginning of the season, i really didn't want him on the gate with 12 yr olds either. but, i understand 1 gate drop is a must and have dealt with the 'please don't jump on my kid' mom anxiety.
how would it benefit promoters...maybe it will, maybe it won't. maybe you have a few 7/8 yr olds that want to ride their 65, but don't want to get smoked (even if they don on the track but not on paper), and don't want to be in a 'beginner' class. 6 in one hand...half a dozen in the other. but, if one hand helps build the confidence in the riders of the future, wouldn't that be a benefit to the promoter?
funny you mention the older classes as i just had this discussion with my husband who is trying his hand in the 30+ class. his class was lined up with 3 other classes at a recent race. i think they age range was like 16-30+. well, he didn't get the checkered flag and when i mentioned that i didn't think the others were in his class, he told me that classes don't matter, racing is racing. classes are only to make you feel good when you sign up and when you go home ;-) like i said, 6 in one hand, half a dozen in the other.
you can argue both sides, but in the end, do what you got to do to keep your head above water so we can have decent places to go!