how does it make more sense? you end up racing less than 10 people and get an easier streak
the reason it ends up less than 10 is because those people crashed/got bored or something, most people with a chance of winning won't quit or enter /tt or something so they won't actually have an impact on the winner of the race meaning that if they leave, the winner shouldn't suffer. earlier today (yesterday if you're gonna be that guy) i started a race with 15 people, by the time it was finished there was about 8, then in the next race it was back up to 15+, people leave racemode when they fail or have no chance of doing well, so the person who is on the streak shouldn't be the one who suffers.
this way makes much more sense because it works in the opposite way too, say if you start a race and only 8 people are in racemode and suddenly more people join half way through, those newcomers have no chance of winning but they still allow you to continue your streak.