This is how races should be done too IMO until there is a significant sized (30 riders?) group. As posted above many groups are similar speeds.

I've watched a lot of fields of 1-4 riders (seen them start, they are beyond boring to watch). The Valley of the Sun stage race 2015 had 1 rider in category. It costs the promoters way too much money to host a race where few show. Then there is pressure for promoters to pay purses (I don't like money in amateur races, I'd rather see more races) equal in men and women's races even if the fields are half the size, and races shorter and fees lower. The age divisions also have issues. I won't wax on, but, yea - I like the speed divisions the most.

If everyone just raced according to speed and your group was based on your speed/results many issues would go away. As in fondos the promoter can have hard awards for 1st junior, 1st woman, first whatever, and if there is no class that fits you, you can just lookup the results as you were all racing together.

In the cloud/social media/GPS/Strava world this also cleans up the popular arm chair Monday morning QB comparisons if everyone races together. I am constantly reading some Facebook post or comment about so-and-so's Strava time from a race compared to another race - which is silly, but done too often. When you put everyone together by speed, comparing time is the same as comparing placing, and it does mean something.