I think it's probably true that there tends to be more 8 point frames than 10 point frames across the board. However, local genetics plays a major role. In one area I hunt, most of the larger bucks are 8 point frame, while another area, a few miles away, the bucks tend to have more 10 point racks. (Unfortunately, a few years back, I missed a "gimmie" on one of those big 8-pointers but at least I found one of his sheds which scores in the low 70's as a typical and has a 15 inch G2. Unfortunately for me though, that's the last clue of him I've turned up to this point!)
Personally, I'd rather shoot a big 8 than a 10. Eight pointers in the 140 inch and above range, especially, to my eyes, look so much bigger than a similar scoring ten, mostly because of increased tine lengh.
Good Hunting...Rich