Sounds like an odd question - maybe its already been answered but I couldnt see it anywhere.
With previous Forza games you could start a lobby yourself. You could even start a race. Which was pretty handy. It meant
A. you could play around with the settings - and test them out to see if they did what you want
B. you could having figure out what settings you wanted setup a lobby prior to starting a game with friends.
Does anyone know why they changed this so you need 2 people in there now ? Doesnt seem like it helps anyone or anything. Just a pointless restriction ?
There was a bunch of other things in earlier games too - you could create different groups with various settings in each (EG a power handicap), You could control the AI cars in a race - you could even cherry pick what each car was. Maybe some of these are still options - suspect not (im sure I looked at launch and sorta lost interest a little when they were not)